Disinfection of air using an iodine/resin disinfectant

ABSTRACT

The present invention relates to iodine demand disinfectants. It relates in particular to a process for preparing a polyiodide-resin for use as an iodine demand disinfectant wherein a porous strong base anion exchange resin in a salt form, is contacted with a material capable of donating a member absorbable by the resin so as to convert the resin to the polyiodide-resin. The adsorbable member is selected from the group comprising I 2  and polyiodide ion having a valence of -1. The process is characterized in that conversion of the anion exchange resin to the polyiodide-resin is effected at elevated temperature and elevated pressure, the elevated temperature being 100 degrees C. or higher, the elevated pressure being greater than atmospheric pressure. The present invention also relates to disinfectant substance comprising an iodine (impregnated) resin as produced by the above process.

This is a divisional of application Ser. No. 08/256,425, filed Jul. 12,1994 U.S. Pat. No. 5,639,452 filed as PCT/CA93/00378 on Sep. 15, 1993,which application is a continuation-in-part of U.S. patent applicationSer. No. 07/957,307 filed Sep. 16, 1992, abandoned, and of U.S. patentapplication Ser. No. 08/047,535 filed on Apr. 19, 1993, abandoned.

The present invention relates to a disinfectant substance comprising aniodine (impregnated) resin and to a process for the preparation thereof.The iodine/resin disinfectant may be used to sterilize a fluid such as,for example, water, air, as well as fluid exudate secreted at bodylesions or traumas such as at cuts, burns, etc.; thus, the disinfectantmay be used to devitalize microorganisms (e.g. bacteria, viruses, etc. .. . ) which may be present in the fluid (e.g. water, air, pus and thelike). The treatment of fluid, such as water or air, with aniodine/resin disinfectant of the present invention may leave behindnon-detectable (or acceptable) residual diatomic iodine in the fluid(e.g. water or air). The present invention in particular relates to ademand type broad spectrum resin-polyiodide (e.g. water, air, wound)disinfectant.

Diatomic halogen (such as I₂, Cl₂, Br₂, etc. . . . ) has traditionallybeen used to disinfect water. Diatomic chlorine, for example, is awidely exploited disinfectant for controlling or eliminatingmicro-organisms which may be present in water. A disadvantage of asterilization regime which exploits diatomic halogen is that the regimemay leave behind unacceptable (residual) levels of halogen in the wateronce sterilization is complete.

An iodine/resin product has, however, been proposed for use as a demanddisinfectant, namely a disinfectant wherein iodine is released almostentirely on a demand-action basis. U.S. Pat. Nos. 3,817,860, 3,923,665,4,238,477 and 4,420,590 teach such a demand disinfectant wherein iodineis the active disinfectant agent; the entire contents of each of thesepatents is incorporated herein by reference. In accordance with theteachings of these patents the resin product may be used without fear ofintroducing unacceptable concentrations of diatomic iodine into thewater to be sterilized.

U.S. Pat. Nos. 3,817,860 and 3,923,665 teach an iodine/resin demanddisinfectant which is the reaction product obtained by contacting astrong base anion exchange resin with a suitable source of triiodideions. The reaction product is taught as being very stable in the sensethat the amount of iodine (e.g. I₂) released into water from thereaction product is sufficiently low that the water disinfected therebyis immediately ready for use, ie. as drinking water.

In accordance with the teachings of U.S. Pat. Nos. 3,817,860 and3,923,665 the procedure for preparing the iodine/resin comprises forminga triiodide ion (solution or sludge) by dissolving diatomic iodine in awater solution of a suitable alkali metal halide (e.g. KI, NaI, . . . ).The triiodide solution is in particular taught as being made with aminimal (i.e. minor) water content just sufficient to avoid causing theI₂ to crystallize out; see example 1 of U.S. Pat. No. 3,923,665. Theresulting (solution) containing the triiodide ion is then contacted withthe starting resin (under ambient conditions with respect to temperature(i.e. 25 to 30° C.) and pressure), the triiodide ions exchanging withthe anion of the resin (e.g. exchange with chlorine, sulfate, etc., . .. ). The starting resin is taught as being a porous granular strong baseanion exchange resin having strongly basic groups in a salt form whereinthe anion thereof is exchangeable with triiodide ions. In accordancewith the teachings of the above prior art references contacting iscontinued until the desired amount of triiodide has reacted with thestrongly basic groups such that bacterially contaminated water isdisinfected when passed through a bed of the obtained resin. After asuitable contact time the iodine/resin is (water) washed to removewater-elutable iodine from the resin product.

However, as indicated in U.S. Pat. No. 4,238,477, it is difficult to usethe procedures outlined in the two previously mentioned U.S. patents soas to obtain a homogeneous iodine/resin product containing onlytriiodide anions and wherein all of the active sites of the resin havebeen converted to triiodide ions.

Accordingly, U.S. Pat. No. 4,238,477 teaches an alternate processwhereby the iodine/resin may be produced. In accordance with thisalternate impregnation/contact process, a suitable resin in the iodideform (I⁻) is contacted with water comprising diatomic iodine (I₂) insolution, the water being recycled between a source of a predeterminedamount of diatomic iodine and the resin. The process as taught by thislatter patent, however, is a relatively complicated system of pumps,vessels, heaters, etc.; by exploiting a fluidized bed, it in particularmay lead to a significant degree of resin bead attrition, i.e. particlebreakup.

The processes as taught in U.S. Pat. Nos. 3,817,860 and 3,923,665 arecarried out at ambient temperature and ambient pressure conditions. TheU.S. Pat. No. 4,238,477 teaches that the contact may occur at a highertemperature such as 60 to 95° C. but that the temperature must be anon-boiling temperature (with respect to water); see column 3 lines 55to 66.

The above referred to U.S. patents teach the use of the demanddisinfectant iodinated resins for treating water; see also U.S. Pat.Nos. 4,298,475 and 4,995,976 which teach water purification devices orsystems which exploit iodinated resins. None of these patents teachesthe use of the iodinated resins for the purpose of sterilizing air.

It is also known to use iodine tincture for sterilising wounds. Thesterilisation effect of iodine tincture is short lived; this means thatthe tincture must be reapplied on a regular basis to maintain thesterilisation effect. However, such solutions may also damage or destroythe tissue around the wound if applied too liberally and too often.Additionally, the direct application of such solutions to a lesion orwound is usually accompanied by a painful sensation.

Accordingly it would be advantageous to have a iodine/resin productwhich has improved characteristics over known or commercially availableiodine/resin disinfectant products.

It would also be advantageous to have an alternate process for thepreparation of a iodine/resin product (which has improvedcharacteristics over the previously known iodine/resin).

It would be advantageous to have an alternative effective demanddisinfectant (e.g. bactericidal) resin and an effective technique forthe manufacture thereof. It would, in particular, be advantageous tohave an iodine/resin demand disinfectant having a relatively low levelof iodine bleed into a fluid (such as water or air) being treated aswell as an iodine impregnation process for obtaining such iodinatedresin.

It would also be advantageous to have a means whereby lesions, such asfor example wounds or burns, may be treated in order to facilitatehealing by devitalising microorganisms which may already be in the areaof the lesion and further to prevent microorganisms from having accessto such lesion (i.e. a dressing), i.e. to inhibit access from anyoutside biovectors such as for example airborne, waterborne, spitalborne, blood borne, particulate borne microorganisms and the like.

It would additionally be advantageous to have a means for inhibiting orpreventing microorganisms from contacting predetermined areas of thebody such as the skin (e.g. a protective textile for making protectiveclothing).

In accordance with a general aspect, the present invention provides aprocess for preparing a demand disinfectant resin, said disinfectantresin being an iodinated strong base anion exchange resin, (i.e. ademand disinfectant-resin comprising polyiodide ions, having a valenceof -1, the ions being absorbed or impregnated into the resin as hereindescribed),

the process comprising a conversion step, the conversion step comprisingcontacting a porous strong base anion exchange resin in a salt form witha sufficient amount of an iodine-substance absorbable by the anionexchange resin such that the anion exchange resin absorbs saidiodine-substance so as to convert the anion exchange resin to thedisinfectant-resin, said iodine-substance being selected from the groupcomprising I₂ (i.e. diatomic iodine) and polyiodide ions having avalence of -1,

characterized in that for the conversion step at least a portion of theabsorption of iodine-substance is effected at elevated temperature andat elevated pressure, said elevated temperature being 100° C. or higher(e.g. a temperature higher than 100° C. such as, for example, 102° C.,103° C., 104° C., 105° C., 110° C., 115° C., 150° C., etc.), saidelevated pressure being greater than atmospheric pressure (e.g. apressure greater than barometric pressure such as for example 2 psig, 3psig, 4 psig, 5 psig, 15 psig, 25 psig, 35 psig, 100 psig, etc.).

In accordance with the present invention the disinfectant-resin may beone in which diatomic iodine is incorporated. The disinfectantpolyiodide-resin may in particular be triiodide-resin. Thus, forexample, the iodine-substance may comprise triiodide ion of formula I₃⁻, i.e. so as to form a disinfectant-resin which comprises (absorbed)triiodide ions of formula I₃ ⁻.

The terms "triiodide", "triiodide ion" and the like, as used in thecontext herein, refer to or characterize a substance or a complex ascontaining three iodine atoms and which has a valence of -1. Thetriiodide ion herein therefore is a complex ion which may be consideredas comprising molecular iodine (i.e. iodine as I₂) and an iodine ion(i.e. I⁻). Similarly the terms "polyiodide". "polyiodide ions" and thelike, refer to or characterize a substance or a complex as having threeor more iodine atoms and which may be formed if more of the moleculariodine combines with the monovalent triiodide ion. These terms are moreparticularly described in the above referred to U.S. patents.

In accordance with a further aspect, the present invention provides aprocess for preparing a demand disinfectant resin, said disinfectantresin being an iodinated strong base anion exchange resin, (i.e. ademand disinfectant-resin comprising polyiodide ions, having a valenceof -1, the ions being absorbed or impregnated into the resin as hereindescribed),

the process comprising a conversion step, the conversion step comprisingcontacting a porous strong base anion exchange resin in a salt formother than the iodide form I⁻, with a sufficient amount of aniodine-substance absorbable by the anion exchange resin such that theanion exchange resin absorbs said iodine-substance so as to convert theanion exchange resin to the disinfectant-resin, said iodine-substancebeing selected from the group comprising polyiodide ions having avalence of -1,

characterized in that for the conversion step at least a portion of theabsorption of iodine-substance is effected at elevated temperature andat elevated pressure, said elevated temperature being 100° C. or higher(e.g. a temperature higher than 100° C.), said elevated pressure beinggreater than atmospheric pressure (e.g. a pressure greater thanbarometric pressure).

The strong base anion exchange resin may be in a salt form such as forexample a chloride or hydroxyl form.

The conversion in accordance with the present invention may essentiallyor at least partially be effected at said elevated temperature andelevated pressure. The conversion, in accordance with the presentinvention, may, thus for example, be effected in one, two or morestages. For example, the elevated pressure/temperature conditions may bedivided between two different pairs of elevated pressure/temperatureconditions, e.g. an initial pressure of 15 psig and a temperature of121° C. and a subsequent pressure of 5 psig and a temperature of 115° C.

If the conversion is to be carried out in two stages, it may forexample, comprise a first stage followed by a second stage. The firststage may, for example, be effected at low temperature conditions (e.g.at ambient temperature and ambient pressure conditions) whereas thesecond stage may be effected at elevated conditions such as describedherein.

Thus, the present invention, in accordance with another aspect providesa process for preparing a demand disinfectant resin, said disinfectantresin being an iodinated strong base anion exchange resin, (i.e. ademand disinfectant-resin comprising polyiodide ions, having a valenceof -1, the ions being absorbed or impregnated into the resin as hereindescribed),

the process comprising a conversion step, the conversion step comprisingcontacting a porous strong base anion exchange resin in a salt form witha sufficient amount of an iodine-substance absorbable by the anionexchange resin such that the anion exchange resin absorbs saidiodine-substance so as to convert the anion exchange resin to the demanddisinfectant resin, said iodine-substance being selected from the groupcomprising I₂ and polyiodide ions having a valence of -1,

characterized

in that said conversion step comprises an initial conversion stagefollowed by a second conversion stage,

in that said initial conversion stage comprises contacting the anionexchange resin with the iodine-substance at a temperature of 100° C. orlower so as to obtain an intermediate composition, said intermediatecomposition comprising residual absorbable iodine-substance and anintermediate iodinated resin, (i.e. a resin comprising absorbedpolyiodide ions having a valence of -1), and

in that said second conversion stage comprises subjecting theintermediate composition to elevated temperature and elevated pressure,said elevated temperature being 100° C. or higher (e.g. a temperaturehigher than 100° C.), said elevated pressure being greater thanatmospheric pressure.

In accordance with a further particular aspect, the present inventionprovides a process for preparing a demand disinfectant resin, saiddisinfectant resin being an iodinated strong base anion exchange resin,(i.e. a demand disinfectant-resin comprising polyiodide ions, having avalence of -1, the ions being absorbed or impregnated into the resin asherein described),

the process comprising a conversion step, the conversion step comprisingcontacting a porous strong base anion exchange resin in a salt formother than the iodide form I⁻ with a sufficient amount of aniodine-substance absorbable by the anion exchange resin such that theanion exchange resin absorbs said iodine-substance so as to convert theanion exchange resin to the disinfectant-resin, said iodine-substancebeing selected from the group comprising polyiodide ions having avalence of -1,

characterized

in that said conversion step comprises an initial conversion stagefollowed by a second conversion stage,

in that said initial conversion stage comprises contacting the anionexchange resin with the iodine-substance at a temperature of 100° C. orlower so as to obtain an intermediate composition, said intermediatecomposition comprising residual absorbable iodine-substance and anintermediate iodinated resin (i.e. a resin comprising absorbedpolyiodide ions having a valence of -1),

and

in that said second conversion stage comprises subjecting theintermediate composition to elevated temperature and elevated pressure,said elevated temperature being 100° C. or higher (e.g. a temperaturehigher than 100° C.), said elevated pressure being greater thanatmospheric pressure.

In accordance with the present invention, for the first stage, the lowtemperature may, for example, be a non-boiling temperature of not morethan 95° C.; e.g. 15 to 60° C.; e.g. ambient temperature or roomtemperature such as a temperature of from about 15° C. to about 40° C.,e.g. 20 to 30° C. The pressure associated with the low temperaturecondition of the first stage may, for example, be a pressure of from 0(zero) to less than 2 psig; the pressure may in particular beessentially ambient pressure (i.e. a pressure of less than 1 psig to 0(zero) psig; 0 psig reflecting barometric or atmospheric pressure).

In accordance with the present invention, for the second stage, theelevated temperature may, for example, be: a temperature of 102° C. orhigher; e.g. 105° C. or higher; e.g. 110° C. or higher; e.g. 115° C. orhigher; e.g. up to 150° C. to 210° C.; e.g. 115° C. to 135° C. Theelevated pressure associated with the elevated temperature condition ofthe second stage may, for example, be: a pressure of 2 psig or greater;e.g. 5 psig or greater; e.g. 15 psig to 35 psig; e.g. up to 100 psig.

The present invention further relates to any demand disinfectant resin,the disinfectant resin being an iodinated strong base anion exchangeresin which is the same as an iodinated strong base anion exchange resinprepared in accordance with a process as defined herein; an iodinatedresin the same as a resin prepared in accordance with the (particular)process described herein is one which has the same low iodine bleedcharacteristic, i.e. the iodine is (more) tenaciously associated withthe resin than for previously known iodinated resins. It in particularrelates to a demand disinfectant resin, the disinfectant resin being aniodinated strong base anion exchange resin whenever prepared inaccordance with a process as defined herein.

The present invention also relates to the use of iodinated resins todisinfect fluids containing microorganisms, such fluids including air,water, pus, and the like. The iodinated resin may for example be a knownresin such as discussed herein, a resin in accordance with the presentinvention, nylon based resin beads impregnated with iodine (such as MCVresin from MCV Tech. Intn'l Inc.), and the like.

Thus the present invention also provides a method for disinfecting aircontaining airborne microorganisms, said method comprising passing saidair over a disinfectant resin such that airborne microorganisms contactsaid resin and are devitalized thereby, said disinfectant resincomprising an iodinated resin. The disinfectant resin may, for example,be a demand disinfectant resin. The disinfectant resin may, for example,comprise an iodinated strong base anion exchange resin.

The present invention further provides a system for disinfecting aircontaining airborne microorganisms, said system comprising

means for providing an air path for the movement of air therethrough,

and

a disinfectant resin disposed in said air path such that airbornemicroorganisms in air passing through said air path are able to contactsaid resin and be devitalized thereby,

said disinfectant resin comprising an iodinated resin. The disinfectantresin may, for example, be a demand disinfectant resin. The disinfectantresin may, for example, comprise an iodinated strong base anion exchangeresin.

The present invention additionally provides a combination comprising

a disinfectant component

and

a carrier component,

said disinfectant component comprising particles of an iodinated resin,

said particles of said disinfectant component being held (e.g. fixed) tosaid carrier component. The disinfectant component may, for example, bea demand disinfectant component. The disinfectant resin may, forexample, comprise an iodinated strong base anion exchange resin. Thecombination may be used as a means for providing a barrier or shield forthe body against microorganisms. The combination may thus, for example,be incorporated into a textile or other wearing apparel startingmaterial in the form of a layer (e.g. a liner layer). The obtained rawwearing apparel material may then be used to make a protective garment,glove, sock, footwear (e.g. shoe), helmet, face mask and the like; theobtained wearing apparel may be worn in hazardous environments toprotect the wearer from contact with viable microorganisms. Thecombination as desired or as necessary may be flexible or stiff;depending on the nature of the carrier component and also on the form ofthe resin (e.g. plate, particle, etc.).

The present invention in a more particular aspect provides asterilisation dressing, for being applied to a lesion, (such as a sore,a wound (e.g. cut), an ulcer, a boil, an abrasion, a burn or otherlesion of the skin or internal organ), said dressing comprising

a disinfectant component

and

a carrier component,

said disinfectant component comprising particles of an iodinated strongbase anion exchange resin,

said carrier component being configured so as to hold onto particles ofsaid disinfectant component such that microorganisms are able to bebrought into contact with said particles and be devitalised thereby,

said carrier component being of a pharmaceutically acceptable material.The disinfectant component may, for example, be a demand disinfectant.The disinfectant resin may, for example, comprise an iodinated strongbase anion exchange resin. The carrier component may be stiff or it maybe flexible as desired. The (sterilization) dressing may, for example,be applied over a wound or burn and be held in place over the timeperiod needed for the body to repair the damaged area; the dressingduring this time will act not only as a barrier or shield to preventinfectious microorganisms from contacting the lesion but also tosterilize the immediate area around the lesion including sterilising anyfluid exudate such as pus which may exude from the lesion. Surprisingly,it has, for example, been found that even with relatively prolongedexposure of (guinea pig) skin to the active element of the dressing(i.e. the demand disinfectant) no irritation or inflammation was noted.It has also surprisingly been found that the dressing may effectinfectious agents deep beneath the skin or dressing. The healing processmay thus be hastened by the application of a (sterilization) dressing inaccordance with the present invention.

The demand disinfectant for the above mentioned method and system fortreating air as well as for the combination and the dressing may be aniodinated resin produced in accordance with the present invention or itmay be a known demand disinfectant iodinated resin such as for exampleas mentioned herein.

The demand disinfectant depending on the intended use may take on anydesired form; it may be bulk form; it may be in sheet form; it may be inparticulate or granular form (e.g. particles of resin of from 0.2 mm to1 cm in size), etc..

It is to be understood herein, that if a "range" or "group ofsubstances" is mentioned with respect to a particular characteristic(e.g. temperature, presssure, time and the like) of the presentinvention, the present invention relates to and explicitly incorporatesherein each and every specific member and combination of sub-ranges orsub-groups therein whatsoever. Thus, any specified range or group is tobe understood as a shorthand way of referring to each and every memberof a range or group individually as well as each and every possiblesub-ranges or sub-groups encompassed therein; and similarly with respectto any sub-ranges or sub-groups therein. Thus, for example,

with respect to a pressure greater than atmospheric, this is to beunderstood as specifically incorporating herein each and everyindividual pressure state, as well as sub-range, above atmospheric, suchas for example 2 psig, 5 psig, 20 psig, 35.5 psig, 5 to 8 psig, 5 to 35,psig 10 to 25 psig, 20 to 40 psig, 35 to 50 psig, 2 to 100 psig, etc.;

with respect to a temperature greater than 100° C., this is to beunderstood as specifically incorporating herein each and everyindividual temperature state, as well as sub-range, above 100° C., suchas for example 101° C., 105° C. and up, 110° C. and up, 115° C. and up,110 to 135° C., 115° C. to 135° C., 102° C. to 150° C., up to 210° C.,etc.;

with respect to a temperature lower than 100° C., this is to beunderstood as specifically incorporating herein each and everyindividual temperature state, as well as sub-range, below 100° C., suchas for example 15° C. and up, 15° C. to 40° C., 65° C. to 95° C., 95° C.and lower, etc.;

with respect to residence or reaction time, a time of 1 minute or moreis to be understood as specifically incorporating herein each and everyindividual time, as well as sub-range, above 1 minute, such as forexample 1 minute, 3 to 15 minutes, 1 minute to 20 hours, 1 to 3 hours,16 hours, 3 hours to 20 hours etc.;

and similarly with respect to other parameters such as low pressures,concentrations, elements, etc. . . .

It is also to be understood herein that "g" or "gm" is a reference tothe gram weight unit; that "C" is a reference to the celsius temperatureunit; and "psig" is a reference to "pounds per square inch guage".

In drawings which illustrate example embodiments of the presentinvention:

FIG. 1 is a graph of showing the ppm of Iodine in the effluent versusthe total volume of water contacted with a disinfectant-resin bed of theprior art and an example disinfectant resin of the present invention;

FIG. 2 is a graph of the number of microorganisms in effluent versus thetotal volume of contaminated water contacted with a disinfectant resinof the prior art and an example disinfectant resin of the presentinvention;

FIG. 3 is a perspective view of a cartridge which may be used to housean iodinated resin as described herein for use for example in a gasmask;

FIG. 4 is a cross sectional view 4--4 of the cartridge of FIG. 1;

FIG. 5 is a schematic illustration of a system for testing a cartridgecontaining an iodinated resin;

FIG. 6 is a schematic illustration of another type of system for testinga cartridge containing an iodinated resin;

FIG. 7 is a partially cut away perspective view of a sterilisationdressing of tea-bag type construction wherein the iodinated resinparticles are free flowing but are held together by being enveloped by afluid (e.g. air-liquid) permeable envelope of paper, gauze, plasticsmaterial, etc.;

FIG. 8 is a perspective view of a band-aid type sterlization dressing,wherein the iodinated resin particles are fixed to a central portion ofan outer surface of a flexible band-aid carrier;

FIG. 9 is a perspective partially cut away view of a sterilisation foamor sponge type dressing comprising a flexible foam matrix havingiodinated resin particles dispersed therein, the foam matrix having arelatively small pore size structure;

FIG. 10 is a perspective partially cut away view of a sterilisation foamor sponge type dressing comprising a flexible foam matrix havingiodinated resin particles dispersed therein, the foam matrix having arelatively large pore size structure; and

FIG. 11 is a cross sectional view of a sandwich type of textile materialfor use in the preparation of protective clothing, the textile includinga layer of a flexible foam matrix such as is shown in FIG. 10.

In accordance with the present invention, the elevated temperature mayas mentioned above, for example, be in the range of from 105° C. to 150°C.; the elevated pressure may be 5 psig and up.

In accordance with the process of the present invention the anionexchange resin may, for example, as described below, be a quaternaryammonium anion exchange resin; the anion exchange resin may be in thechloride form Cl⁻, in the hydroxyl form OH⁻ ; etc. . . .

In accordance with the present invention the obtained iodide-resin maybe treated prior to use to remove any water-elutable iodine from theiodide-resin. The treatment (e.g. washing) may be continued until nodetectable iodine is found in wash water (the wash water initially beingion free water). Any suitable (known) iodine test procedure may be usedfor iodine detection purposes (see for example the above mentioned U.S.patents.

In accordance with the present invention, the absorbable iodinesubstance may, for example, be provided by a composition consisting ofmixture of KI, I₂ and a minor amount of water, the mole ratio of KI toI₂ initially being about 1; the expression "minor amount of water" asused herein shall be understood as characterizing the amount of water asbeing sufficient to avoid I₂ crystallization.

The present invention in a further aspect provides an enhancediodine/resin demand disinfectant product in which more iodine may bedistributed throughout and be more tenaciously associated with the resin(e.g. beads) than with the previously known or commercially availabletechniques, the disinfectant being produced by a process as describedherein. The invention more particularly provides an enhancedtriiodide-resin disinfectant.

The present invention can be practised with any (known) strong baseanion exchange resin (for example, with those such as are described inmore detail in the above-mentioned United States patents such as U.S.Pat. No. 3,923,665). A quaternary ammonium anion exchange resin is,however, preferred. As used herein, it is to be understood that theexpression "strong base anion exchange resin" designates a class ofresins which either contain strongly basic "cationic" groups, such asquaternary ammonium groups or which have strongly basic properties whichare substantially equivalent to quaternary ammonium exchange resins.U.S. Pat. Nos. 3,923,665 and 3,817,860 identify a number of commerciallyavailable quaternary ammonium resins, as well as other strong baseresins including tertiary sulphonium resins, quaternary phosphoniumresins, alkyl pyridinium resins and the like.

Commercially available quaternary ammonium anion exchange resins whichcan be used in accordance with the present invention include inparticular, Amberlite IRA-401 S, Amberlite IR-400 (Cl⁻) , AmberliteIR-400 (OH⁻), Amberlite IR-402 (Cl⁻), etc., (from Rohm & Hass) which maybe obtained in granular form. These resins may for example, containquaternary ammonium exchange groups which are bonded to styrene-divinylbenzene polymer chains.

The resins which may be used herein may be in a hydroxyl form, achloride form or in another salt (e.g. sulphate) form provided that theanion is exchangeable with the iodine member (e.g. with triiodide ion).

The starting resin may, for example, be granular (i.e. comprise aplurality of particles) such that the final product will likewise have agranular or particulate character; the granular form is advantageous dueto the high surface area provided for contact with microorganisms. Thestarting resin may, for example, comprise granules having a size in therange of from 0.2 mm to 0.8 cm (e.g. of from 0.35 mm to 56 mm).

Commercially available resins such as those mentioned above areavailable in the salt form (e.g. as the chloride) and in the form ofporous granular beads of various mesh sizes; the resin may of course beused in a bulk or massive form such as a plate, sheet, etc..

In accordance with the present invention, for example, a resin may beconverted from a non-iodide form (e.g. a chloride form, a sulphate form)to the I₃ ⁻ form. Suitable halide salts include alkali metal halides(such as KI, Nal, . . . ); potassium iodide is preferred. Alternatively,an iodide form of the resin may be used and the resin contacted with asource of diatomic iodine.

In accordance with the present invention any material or substancecapable of donating an iodine-member absorbable by the anion exchangeresin so as to convert the anion exchange resin to the desiredpolyiodide-resin may be used, as long as the denotable iodine-memberthereof is a polyiodide ion having a valence of -1 and/or diatomiciodine. Examples of such materials in relation to iodine are shown inthe above mentioned U.S. patents; e.g. compositions comprising iodine(I₂) and alkali metal halide (KI, NaI, etc. . . . , KI being preferred)in association with water. Alternatively, if the resin is in an iodidesalt form (I⁻¹), the material may comprise the corresponding iodine ingaseous form.

Thus, for example, if a triiodide-resin is desired the resin may becontacted with an alkali metal iodide/I₂ mix wherein the iodide and thediatomic iodine are present in more or less stoichiometric amounts (i.e.a mole ratio of 1); see the previously mentioned U.S. patents. Byapplying stoichiometric amounts of the iodine ion and iodine molecule(i.e. one mole of I₂ per mole of I⁻¹), the iodide sludge will comprisesubstantially only the triiodide ions. If stoichiometric excessquantities of I₂ are used some of the higher polyiodide ions may beformed. Preferably, no more than the stoichiometric proportions of I⁻and I₂ are used in the initial aqueous starting sludge so thatsubstantially only triiodided attaches to the resin.

For example iodine may be combined with sodium, potassium or ammoniumiodide and some water. The composition will contain monovalent iodineion which will combine with diatonic iodine (I₂) to form polyiodide ion.The molar ratio of iodine ion to diatomic iodine will dictate the natureof the polyiodide ion present, i.e. triiodide ion, mixtures of triiodideion and other higher polyiodides ions, pentaiodide ion, etc. . . . Usingabout 1 mole of iodine ion per mole of diatonic iodine the formation oftriiodide ion will be favoured. If stiochiometric excess of diatoniciodine is used this will favour the formation of higher polyiodides.

The determination of the (total) amount of iodine to be contacted withthe resin, residence times etc. . . . , will depend upon such factors asthe nature of the polyiodide it is desired to introduce into thestructure of a resin; the nature of the starting resin (i.e. porosity,grain size, equivalent exchange capacity of the resin, etc.), etc..Thus, for example, to determine the amount of iodine required to preparea polyiodide resin, the equivalent exchange capacity of the resin needsto be known. If necessary, this can be readily determined for example bythe procedure described in U.S. Pat. No. 3,817,860 (column 9, lines 15to 28). The components of the process may be chosen such that theobtained iodinated strong base anion exchange resin may comprise astrong base anion exchange resin component which represents from 25 to90 (preferably 45 to 65) percent by weight of the total weight of theobtained iodinated resin.

The conversion at elevated conditions, in accordance with the presentinvention, may be effected in a reactor which is pressure sealableduring conversion but which may be opened for recovery of the resinproduct after a predetermined reaction time. The process may thus be abatch process wherein conversion at elevated temperature and pressure iseffected once the reactor is sealed. In accordance with the presentinvention the reactor may be sized and the amount of reactantsdetermined so as to provide a void space in the reactor during reaction.In the case, for example, wherein the material having the denotableiodine-member is a sludge of alkali metal/I₂ and water, the weight ratioof sludge to resin may be 1:1 or higher, eg. 1:1 to 5:1; a weight ratioof 1:1 (if Amberlite 401-S is used as the resin) is preferred so as tominimize the amount of unabsorbed iodine which must be washed from theiodine/resin product.

The high temperature/pressure contact conditions may as mentioned abovebe chosen with a view to maximizing the iodine content of the obtainediodine (e.g. iodine) demand resin.

In accordance with the present invention conversion of the resin to apolyhalide (e.g. I₃ ⁻) form may be effected at elevated temperaturegreater than 100° C., for example in the range of 105° C. to 150° C.(e.g. 110-115° C. to 150° C.); the upper limit of the temperature usedwill, for example, depend on the characteristics of the resin beingused, i.e. the temperature should not be so high as to degrade theresin.

As mentioned in order to effect the conversion at elevated pressure, theconversion may take place in a closed vessel or reactor. The pressure insuch case may be a function of the temperature such that the pressuremay vary with the temperature approximately in accordance with the wellknown gas equation PV=nRT, wherein V=the constant (free) volume of thereactor, n=moles of material in the reactor, R is the universal gasconstant, T is the temperature and P is the pressure. In a closedvessel, the temperature of the system may therefore be used as a meansof achieving or controlling the (desired) pressure in the vesseldepending upon the makeup of the Iodine mix in the reactor. Thus inaccordance with the present invention, a reaction mix disposed in apressure sealed reactor may be, for example, subjected to a temperatureof 105° C. and a pressure of 200 mmHg, the pressure being induced bysteam.

Alternatively, a relatively inert gas may be used to induce and\oraugment the pressure in the reactor. Thus, a pressurized relativelyinert gas may be injected into a sealed reactor. The chosen gas must notunduly interfer with the production of a suitable iodinated resin. Thehigh temperature/pressure treatment may be conducted in a closed reactorin the presence of (trapped air), a non-interfering gas such as iodineitself or of some other relatively inert (noble) gas; the pressure asmentioned above may be augmented by the pressuring gas. Air, carbondioxide, nitrogen or the like may also be used as a pressuring gas, ifdesired, keeping in mind, however, that the use thereof must not undulyinterfer with the production of a suitable iodinated resin. If pressureis to be induced by steam then as mentioned below steps should be takento isolate the reaction mix from (excess) water.

In accordance with the present invention, the elevated pressure is anypressure above ambient. The pressure may, for example, be 1 psig orhigher, e.g in the range from 5 to 50 psig; the upper limit of thepressure used will also, for example, depend on the characteristics ofthe resin being used, i.e. the pressure should not be so high as todegrade the resin.

The residence or contact time at the elevated conditions is variabledepending upon the starting materials, contact conditions and amount of(tenaciously held) iodine it is desired to be absorbed by the anionexchange resin. The contact time may thus take on any value; usually,however, it is to be expected that it will be desired that the contacttime (under the conditions used) be sufficient to maximize the amount of(tenaciously held) iodine absorbed from the material containing theabsorbable iodine moiety. The residence time may for example be aslittle as 5 to 15 minutes (in the case where a preimpregnation step isused as shall be described below) or several hours or more (up to 8 or 9hours or more). The residence time exploited for elevated theconditions, in any event, will as mentioned above depend on the startingmaterial, temperature and pressure conditions, etc. . . . ; it may varyfrom several minutes to 8 or 9 hours or more; the upper time limit willin any event also, for example, depend on the characteristics of theresin being used, i.e. the residence time should not be so high as todegrade the resin.

Preferably, the contact at high temperature/pressure is preceded by aninitial impregnation or absorption step (first stage). Such first stagemay be carried out for only a few minutes (e.g. for from 1 to 10 minutesor more) or for up to 24 hours or more (e.g. for from one hour or morei.e. for from three to twenty-four hours). The time period of theinitial stage may be relatively short. The time period, for example, maybe a few minutes or so and may correpond to the time necessary to justmix the reactants together; in this case the conversion may beconsidered to be essentially carried out in a single stage at elevatedconditions. The residence time of the first stage will also bepredetermined with a view to the end product resin desired. For example,a water containing sludge of triiodide ions can be contacted with a saltform of the starting resin at ambient (i.e. room) temperature andpressure conditions to obtain an intermediate iodide-resin reactionproduct including residual iodine-substance. This step is preferablycarried out in a batch reactor; the obtained intermediate compositioncomprising an intermediate iodide-resin may then be subjected to thehigher temperature and pressure in accordance with the present inventionin batch fashion as well. Such a first stage may be used to initiatebuildup of iodine within the resin matrix.

In accordance with the present invention an iodide-resin demanddisinfectant may, for example, be obtained by

a) bringing a porous, granular, starting resin into contact with anaqueous sludge of iodine and potassium iodide so as to obtain a pastemixture, iodine being present in the sludge essentially as triiodideions, said starting resin being a strong base anion exchange resinhaving strongly basic groups thereof in a salt form the anion of whichis exchangeable with triiodide ions,

b) subjecting the paste mixture to elevated temperature and pressureconditions in an enclosed container or reactor (e.g. autoclave) for apredetermined impregnating duration of time, a void space being providedin the reactor such that contact occurs under an (essentially) iodine(rich) atmosphere,

and

c) washing the obtained iodide-resin product (with a suitable (i.e.purity) washing liquid, (e.g. deionised water, R/O water (at 45° C.),etc.) to remove water elutable iodine such as KI from the surface of theresin so that on drying no iodine (KI) crystals will form on the surfaceof the iodine/resin; R/O water, is water obtained using double reverseosmosis. R/O water is defined below.

More particularly an iodide/resin demand disinfectant may be obtainedusing the following sequence of steps:

1. The resin is purified by triple passage of water and then disposed inethanol in an electrosonic bath and flushed with water and drip dried;

2. (Essentially) stoichiometric amounts of I₂ and potassium iodide areadmixed with a minimum amount of water which is just sufficient toobtain an I₃ - slurry or sludge (with, if desired, very low heating);

3. The resin is admixed with the above-minimal water slurry in smallaliquats so as to obtain a predetermined weight ratio of slurry to resin(e.g. a 50:50 weight ratio);

4. The resin-slurry mixture is then placed in a shaking bath atatmospheric pressure in a closed, air-tight container (if necessary thecontainer being provided with a small pressure release valve or openingthe purpose of which will be hereinafter explained) for a predeterminedtime period (e.g. for up to, for example, sixteen to twenty-four hoursor more [e.g. a week if desired]) to form an intermediate resincomposition;

5. The container containing the reaction mixture is then disposed in a(steam) autoclave and heated at high temperature, (e.g. 120° C.) toprovide a super atmospheric pressure therein (with the small valve openif the container walls would not be able to resist the pressure to beexerted within the autoclave) for a predetermined residence time (e.g. aresidence time of about fifteen minutes) calculated from the time themixture reaches the predetermined high temperature (e.g. 120° C.).

6. The autoclave is removed from the heat and as soon as the pressure isequalized to atmospheric, the internal container is removed and theresin product is washed (e.g. six times) with R/O water until the washwater comes out with a total iodine content of less than 0.1 parts permillion.

A small hole is necessary when a container such as a glass flask is usedin order to avoid a too great pressure difference being built up betweenthe interior of the flask and the interior of the autoclave which mightcause the flask to collapse. The hole in any event is just large enoughto more or less allow for the equalization of pressure and to maintain apositive pressure in the flask relative to the interior of the autoclavesuch that any foreign material such as water vapour is inhibited fromflowing into the flask. A more sturdy pressure resistant container couldof course be used such that, depending on the construction of thecontainer and the temperature/pressure conditions prevailing in theautoclave, the hole may be avoided. Alternatively, instead of using aseparate container to hold the reaction mix and placing it in a separateautoclave, a single autoclave/container may be used serving to hold andheat the reaction mix under pressure; such a container must of course beconstructed so as to be able to resist the predetermined reactionconditions.

The iodide-resin compound formed as described herein can be used as ademand disinfectant to disinfect water by batch contacting thecontaminated water with the resin; continuous processing as mentioned inU.S. Pat. No. 3,923,665 is also possible. Thus water containing viablebacteria (to be killed) may be passed through a fixed bed of porousgranular iodine/resin material. The maximum permissible flow rates fortotal bacterial sterilization may vary with the concentration of thepolyiodide (e.g. triiodide) groups in the resin, bed depth, bacterialcount, etc. . . . The disinfection process may be monitored by takingsamples of water after passage through the bed. Potable innocuous watermay thus be readily produced in accordance with the present inventionwithout the incorporation of objectionable amounts of free iodinetherein as a result. The resin may be used with any (known) watertreating devices such as for example those shown in U.S. Pat. Nos.4,749,484 and 4,978,449.

In accordance with a further aspect, however, as mentioned above, thepresent invention also provides a method for disinfecting air containingairborne microorganisms. The method may comprise passing the air over ademand disinfectant resin such that airborne microorganisms contact saidresin and are devitalized thereby, the demand disinfectant resincomprising an iodinated strong base anion exchange resin. The presentinvention in particular provides a method for disinfecting aircontaining airborne microorganisms, said method comprising passing aircontaining airborne microorganisms through air path means anddisinfecting such air in said air path means by passing such air over ademand disinfectant resin such that airborne microorganisms contact saidresins and are devitalized thereby, said demand disinfectant resincomprising an iodinated strong base anion exchange resin. The methodmay, for example, include passing the air through a bed of granules ofiodinated resin so that the air courses over the granules (in aserpentine manner) as the air makes its way through the bed. The maximumpermissible flow rates for total bacterial sterilization may vary withthe concentration of the polyiodide groups in the resin, bed depth,bacterial count, etc. . . . The iodinated strong base anion exchangeresin may comprise a strong base anion exchange resin component whichrepresents from 25 to 90 (preferably 45 to 65) percent by weight of thetotal weight of the iodinated resin.

In accordance with an additional aspect, the present invention providesa system for disinfecting air containing airborne microorganisms, saidsystem, for example, comprising

means for providing an air path for the movement of air therethrough,

and

a demand disinfectant resin disposed in said air path such that airbornemicroorganisms in air passing through said air path are able to contactsaid resin and be devitalized thereby,

said demand disinfectant comprising an iodinated strong base anionexchange resin.

An air path means may define an air inlet and an air outlet. The resinmay be disposed between said inlet and outlet or be disposed at theinlet or outlet. The air path means may take any form. It may take theform of ductwork in a forced air ventilation system with the demanddisinfectant comprising a bed of resin granules through which the air ismade to pass, the bed otherwise blocking off the air path. Alternativelythe air path means may be defined by a cartridge used for a gas mask,the cartridge having an inlet and an outlet for air; the iodinated resinfor the cartridge may, if desired, be present as a bed of granules,granules incorporated into a (fluid) porous carrier (e.g. tissue,polyurethane foam, etc.) or alternatively take a more massive form suchas a plate(s), a tube(s), a block(s), etc.. Cartridge type gas masks areknown; such gas masks may be obtained for example from Eastern SafetyEquipment Co., Mosport, N.Y., USA.

The C-50 cartridge from a gas mask (from Glendale ProtectingTechnologies Inc. Woodbury, N.Y., USA) may for example be adapted tohold a bed of resin of granules of the present invention. Referring toFIG. 3, the cartridge 1 comprises an a hollow, open ended, thin-walled,tubular body of circular cross section. The wall 2 may for example be ofnylon. The open ends of the cartridge are each blocked off by somesuitable mesh like support material (e.g. 10 micron polypropylene mesh)which is held in place in any suitable known manner such as by glues,spring clip, etc.; the mesh support shown in FIG.3 has a referencenumeral 3. Referring to FIG. 4, the iodinated granular resin bed 4occupies the entire space between the mesh supports 3 and 3'; althoughthe granular resin is more or less tightly packed between the meshsupports 3 and 3', there are still air spaces between the granules forthe passage of air through the granular bed. The mesh supports each haveopenings small enough to retain the iodinated resin in place whileallowing air to pass therethrough into the and through the supportedresin bed 4. The cartridge as shown in FIG. 4 may include a downstreambed 5 of granules of activated carbon, catalyst, or iodine absorbentresins, to scavenge any iodine liberated from the iodinated resin 4. Theactivated carbon bed 5 is held in place by a mesh support 3' and anadditional mesh 6. The bed depth of the resin and carbon is shown asabout 2.5 cm; wheras the bed diameter is about 8 cm. If the iodinatedresin made in accordance with the process of the present invention isused the carbon bed may be omitted, i.e. only the iodinated resin bed 4may be present in the cartridge as the active component (in the examplesbelow, unless the contrary is indicated, the cartridges do not includeany carbon bed); in this case the bed depth may, for example, be less2.5 cm, e.g. 0.1 cm, 0.25 cm, 0.5 cm, 0.85 cm, 1.15 cm, etc.. Such acartridge may be disposed in an air path as shown for example in FIGS. 5and 6 which will be discussed below.

The resin disposed in the air path could of course take on any formother than granules such as blocks, plates, tubes etc..

The iodinated demand disinfectant resin for air treatment may be any(known) iodinated resin so long as the iodinated resin is capable ofdevitalizing airborne microorganisms (i.e. microorganisms transported byair) coming into contact therewith. It may, for example, be a resin asproposed in U.S. Pat. Nos. 3,923,665 and 4,238,477; in this case,however, it may be necessary to use the resin in conjunction with aniodine scavenging material if the resin gives up too much iodine to theair. The iodine scavenging material may be an activated carbon materialor an un-iodinated strong base anion exchange resin as described herein.

Alternatively, as mentioned above, iodinated resin may advantageously bea resin made in accordance with the present invention; in this case theresin need not be used in conjunction with an iodine scavenging materialsuch as a (known) exchange resin, activated carbon, catalyst, etc.,since an iodinated resin made in accordance with the process of thepresent invention may liberate iodine into the air in an amount belowacceptable threshold limits for breathing by human beings.

If desired the iodinated resin for the treatment of air or water may besome type of mixture of iodinated resins, e.g. a mixture of a knowniodinated resin and an iodinated resin prepared in accordance herewith.

As mentioned above, the present invention in a further aspect provides acombination which may act as a sterilization barrier with respect tomicroorganisms. The sterilization combination may, for example, beincorporated into protective wearing apparel or be configured as asterilization dressing for lesions such as for example, wounds andburns; the sterilisation barrier combination can be configured to be ornot to be air breathable.

A sterilization dressing of the present invention advantageously maytake the form of a flexible porous cellular polymeric foam sheet havinga spongy aspect and having dispersed within the polymeric matrix thereofparticles of a demand disinfectant comprising a (known) iodinated resinor an iodinated resin as described herein. The sterilization sheet maybe placed over a burn area to maintain the burn area in a sterilizedstate during the healing process. The disinfectant particles aredistributed throughout the polymeric matrix and have surfaces projectinginto the open pores of the spongy matrix; the spongy matrix acts as asponge so that on the body side thereof it can soak up fluid such as puswhich exude from the burn lesion. Once within the body of the matrix anymicroorganisms in the fluid or pus can contact the disinfectant resinparticles and become devitalized as a result. On the other hand, anymicroorganisms on the opposite side of the sterilization barrier whichattempt to pass through the barrier are also subject to being contactedwith the disinfectant and are also devitalised.

A (flexible) phamaceutically acceptable hydrophilic foam matrix may beobtained by reacting water with HYPOL™ foamable hydrophilic polyurethanepolymer; the HYPOL™ polymer starting material may be obtained from W.R.Grace & Co. Lexintington Mass. U.S.A.. Water reacts to cross link theHYPOL™ polymer; if water is added quickly or at relatively hightemperature foaming occurs and a foam product is obtained.

The carrier component may, as necessary, also be oil or fat loving, e.g.for dealing with individuals with high cholesterol levels.

If desired the iodinated resin for the sterilisation combination may besome type known iodinated resin, a resin prepared in accordanceherewith, or a mixture of iodinated resins, e.g. a mixture of a knowniodinated resin and an iodinated resin prepared in accordance herewith.

FIGS. 7 to 11 which illustrate a number of example embodiements ofsterilisation barrier combinations of the present invention will bediscussed below; these combinations are also described in example 15below.

Turning back to the process of the present invention, if commerciallyavailable materials are to be used to make the iodine/resin then,depending on the purity thereof, the starting materials may have to betreated to remove components which may interfer with the absorption ofthe halide into the resin. Water if present in the initial reaction mixshould be free of interfering elements such as interfering ions.Distilled or ion free water is preferably used for washing.

The following materials may be used to prepare a triiodide resin inaccordance with the present invention:

a) Amberlite 401-S (from Rohm & Hass) a strong base anion exchange resinin granular form, having the following characteristics:

support matrix--styrene/divinyl benzene polymer

anion--chlorine

density--1.06

effective size (diameter)--0.52 mm

total exchange capacity--0.8 meq/ml

working Ph range--0 to 11

moisture content--62%

working temperature--170° F. or less

b) I₂ (solid)--U.S.P. grade (from Fisher Scientific)

c) Potassium iodide (KI)--U.S.P. grade (from Fisher Scientific)

d) Water--ultra pure: obtained using double reverse osmosis (i.e. hereinsometimes referred to simply as R/O water)

Ethanol--U.S.P. grade (from Fisher Scientific)

Using the above substances a resin cramed with triiodide (i.e. atriiodide jam-backed resin) may be obtained as indicated in thefollowing examples.

For the following examples, the following procedure for the evaluationof iodine (I²) and Iodide (I⁻), was conducted according to "standardmethods for the examination of water and wastewater 17e Ed.":

Iodine method: mercuric chloride added to aqueous elemental iodinesolutions causes complete hydrolysis of iodine and the stoichiometricproduction of hypoiodous acid. The compound 4, 4', 4" methylidynetris(leuco crystal violet) reacts with the hypoiodous acid to form crystalviolet dye. The maximum absorbance of the crystal violet dye solution isproduced in the Ph range 3.5-4.0 and measured at a wavelength of 592 nm.The absorbance follows beers' law over a wide range of iodineconcentration. Iodine can be measured in the presence of max. 50 PPMiodide ions without interference.

Iodide method: iodide is selectively oxidized to iodine by the additionof potassium peroxymonosulfate. The iodine produced reactsinstantaneously with the indicator reagent leuco crystal violet over thesame conditions described previously for iodine methods. Totaliodine+iodide results from this procedure and iodide is calculated fromsubstraction of iodine concentration.

Readings were performed on a 1 kb spectrophotometer with a lightpath of1 cm and selected at 592 nm.

EXAMPLE 1 Starting Materials Pretreatment

i) Resin:

The resin is water washed to remove undesirable elements such asmaterial in ionic form. Thus, 100.00 grams of Amberlite 401 S and 200 mlof R/O water are placed in an erlenmyer of 1000 ml. The mixture isshaken for about 3 minutes and the water is then separated from theresin by drip filtration using a wathman filter paper and funnel. Theresin is water washed in the same fashion two more times. After the lastwater wash the resin is drip dried (i.e. again using a wathman filterpaper and funnel) for 15 minutes.

The so recovered water washed resin is subjected to an alcohol wash todissolve undesirable organic material which may be stuck on the resin.Thus, the water washed resin is immersed in 300.00 ml of ethanol. Theresin alcohol mixture is shaken in an ultrasonic bath (Crestultrasonic:1000 Watts--20 liter capacity) for 5 minutes. The alcoholwashed resin is drip dried, again using a wathman filter paper andfunnel.

The "fish" smell is removed from the alcohol washed resin by a finalwater washing stage wherein the wash R/O water is preheated to 40degrees celsius. The alcohol washed resin is placed in an erlenmyerflask (1000 ml) and 250 ml of R/O water at 40 degrees celsius is addedthereto. The water-resin mixture is shaken in a shaking bath (Yamatashaking bath--1 impulse per second/water at 32 degrees celsius) for 5minutes; the water is then removed from the resin by drip drying asmentioned above. The water wash is repeated once more and the resin isdrip dried (for 1 hour) as mentioned above. The washed resin is nowready for use in example 2 hereinbelow.

ii) Iodine sludge containing water:

A mixture of iodine (I₂) and potassium iodide (KI) is prepared by mixingtogether, in an erlenmyer flask, 60.00 grams of iodine and 40.00 gramsof potassium iodide (in both cases on a dry weight basis). ThereafterR/O water is admixed slowly drop by drop with the mixture until ametallic looking sludge is obtained (e.g. with the addition of about5.00 grams of water). The obtained iodine/potassium iodide sludge isthere ready for use in example 2 hereinbelow.

EXAMPLE 2 Low Temperature/Pressure Preimpregnation of Resin with Iodine

The aqueous iodine sludge, as obtained above, is placed in a 500.00 mlErlenmyer flask and is slowly heated to, and maintained at 40 degreescelsius for a few minutes. Once the temperature of the sludge reaches40° C., the washed resin, obtained as above, is slowly admixed with theiodine sludge in 10.00 gram portions every 8 minutes until all of thewashed resin is within the erlenmyer flask. The 500 ml Erlenmeyer flask,containing the obtained starting mix (comprising the I₂ /KI mixture andthe washed resin--approximately 100 grams of each of the startingmaterials), is then sealed with a cork and is placed in a shaking waterbath (Yamato BT:-25) for a period of 16 hours. The temperature of thewater in the shaking bath is maintained at about 20 degrees celsiusduring this time period. At the end of the time period, the Erlenmyerflask is removed from the shaking bath; at this point the removed flaskcontains an preimpregnation mix comprising impregnated resin andremaining I₂ /KI. The Erlenmyer flask is sized such that at the end ofthis (initial) impregnation step, it is only 50% filled with the inprocess resin, etc, i.e. there is a void volume above the impregnationmix.

NOTE: If processing of the treated resin is stopped at this point andthe obtained resin is suitably washed, a resin is obtained in accordancewith the prior art i.e. U.S. Pat. No. 3,923,665.

EXAMPLE 3 Elevated Pressure/Temperature Treatment

The cork of the Erlenmyer flask of EXAMPLE 2 removed from the shakingbath and including the obtained impregnation mix comprising impregnatedresin and remaining I₂ /KI, is changed for a cork having a smalldiameter perforation passing therethrough (i.e. of about 3 mm indiameter). With the perforated cork in place, the Erlenmyer flask isdisposed within a (steam pressure) autoclave along with a suitableamount of water. With the autoclave (pressure) sealed about the flask,the autoclave is heated. Heating proceeds until an internal temperatureand pressure of 115 degrees Celsius and 5 psig respectively is reached.Once those parameters have been reached, they are maintained for 15minutes of processing time. Thereafter the autoclave is allowed toslowly cool for 50 minutes of cooling time (until the internal pressureis equal to ambient pressure) before removing the Erlenmyer flaskcontaining a (raw) product resin demand disinfectant in accordance withthe present invention.

EXAMPLE 4 Washing of Raw Product Resin

The (raw) disinfectant of Example 3 is removed from the autoclaveErlenmyer flask and placed in another 2000 ml Erlenmyer flask. 1400 mlof R/O water at 20 degrees Celsius is admixed with the resin in theflask and the slurry is shaken manually for 3 minutes. The wash water isthereafter removed from the flask by decantation. This wash step isrepeated 7 more times. The entire wash cycle is repeated twice (i.e.eight water washes per cycle) but using water at 45 degrees Celsius forthe next wash cycle and then with water at 20 degrees Celsius for thelast wash cycle. The washed iodine-resin is then ready to use.

EXAMPLE 5 Comparative Physical Data

The following resins were examined with respect to certain physicalcharacteristics:

Resin I-A:

Iodinated resin manufactured in accordance with the present inventioni.e. as obtained from example 4 above.

Resin I-B:

Iodinated resin manufactured in accordance with teachings of the priorart (i.e. U.S. Pat. No. 3,923,665), namely as obtained from example 2above after suitable washing to remove elutable iodine.

Resin I-C:

Iodinated resin manufactured by Water Technology Corporation inMinneapolis (a triiodide based disinfectant resin).

Resin I-D:

Iodinated resin manufactured by Water Technology Corporation inMinneapolis, sold under the Trademark: Pentapure.

In the examples which follow the above resins will be referred to usingthe above designations, i.e. I-D, Resin I-A, etc.

EXAMPLE 5.1 Comparative Wet Tap Density

The resins were examined in a drip dried state, i.e. the resins wereused after being drip dried using wathman filter paper and a funnel (fora 5 minute dry period). 25 ml and 100 ml flasks were used for the study.The flaskes were weighed empty. The flasks were then filled with resinand were then subjected to a manual vibration sequence (approximately 2impulses per second for two minutes) in order to settle the resin, thevolume of the settled resin was then noted. The density was obtained byweighing a filled flask and subtracting the weight of the empty flask soas to obtain the weight (grams) per unit volume (ml) of the resin. Theresults are shown in Table 1 below.

                  TABLE 1                                                         ______________________________________                                               Resin                                                                              density                                                           ______________________________________                                               I-A  1.720 gm/ml                                                         I-B 1.480 gm/ml                                                               I-D 1.600 gm/ml                                                             ______________________________________                                    

EXAMPLE 5.2 Comparative Dry Tap Density

The same procedure as described above for example 5.1 was used exceptthat the initial resin materials were dried simultaneously for 12 hoursat 55 degrees Celsius, and placed in desiccant for 2 hours duringcooling. The results are shown in Table 2 below.

                  TABLE 2                                                         ______________________________________                                               Resin                                                                              Desity                                                            ______________________________________                                               I-A  1.088 gm/ml                                                         I-B 0.957 gm/ml                                                               I-D 1.016 gm/ml                                                             ______________________________________                                    

EXAMPLE 5.3 Iodine Content

1.0 gm of each of the different resins was boiled in 20 ml of water witha concentration of 5% by weight of sodium thiosulphate. Boiling wasconducted for 20 minutes whereafter the water mixture was set aside toair cool for 12 hours. The resin was then recovered and washed with 50ml of a boiling water solution of sodium thiosulphate. Thereafter theresin was dried in an oven for 12 hours at 105 degrees. The iodinedesorbed resin was weighed in each case and the weight difference wasused to calculate the % by weight of the initial resin represented bythe active iodine removed. The results are shown in Table 3 below.

                  TABLE 3                                                         ______________________________________                                        Resin      % by weight iodine                                                 ______________________________________                                        I-A        43.7%                                                                I-B 32.4%                                                                     I-C 30.7%                                                                     I-D 36.7%                                                                   ______________________________________                                    

NOTE: As may be seen from Table 3, the resin in accordance with thepresent invention (i.e resin I-A) has a substantially higher iodinecontent than the commercially available resins or the resin prepared inaccordance with the prior art (i.e. resin I-B).

EXAMPLE 5.4 Comparative Iodine Content in Water During Stagnation

100.00 gm of each resin was mixed with 125 ml of water in Erlenmyerflask which was sealed airtight. The water mixture was allowed to stand20 degrees Celsius for 7 days. A water sample was then taken from eachwater mixture and subjected to a standard method for testing water forthe presence of Iodine using the Leuco Crystal Violet lodometricSpectrophotometer Technique so as to obtain the "ppm" concentration ofiodine in the water. The results are shown in Table 4 below.

                  TABLE 4                                                         ______________________________________                                        Resin     bleed iodine concentration (ppm)                                    ______________________________________                                        I-A       1.7 ppm                                                               I-D 2.5 ppm                                                                 ______________________________________                                    

NOTE: As may be seen from table 4, the resin of the present invention(resin I-A) has a significantly lower iodine bleed lose into water thanthe commercial product (resin I-D).

EXAMPLE 5.5 Resin Size Study

Two grams of dry resin was examined with a microscope having amicrometer scale system and sized by eye. The results are shown in Table5 below.

                  TABLE 5                                                         ______________________________________                                                      Size (ie. approximate effective                                   Resin diameter size) - lowest to highest                                    ______________________________________                                        AMBERLITE I 401 S                                                                           0.35 mm to 0.52 mm                                                I-A 0.60 mm to 1.20 mm                                                        I-B 0.40 mm to 1.00 mm                                                      ______________________________________                                    

EXAMPLE 6

Simultaneous tests were conducted to compare the antimicrobial activityof a disinfectant resin in accordance with the present invention (resinI-A, above) and a prior art disinfectant resin (resin I-D, above). Aseries of batch solutions was prepared; each batch solution contained adifferent microorganism. A batch solution was divided into test portionsso that the comparative tests could be carried out against each of theresins at the same using a respective test portion of the batchsolution; the volume of the test portions was 150 liters. The sameamount of each of the resins was supported in a respective fixed bedconfiguration (i.e. the resins were disposed in a cylinder 1 cm highhaving an internal diameter of 3 cm). The respective test solutions wereallowed to pass downwardly through each of the resins in the samefashion and at the same flow rate (i.e. the test conditions were thesame for each resin). The tests were carried out at ambient conditionsof temperature and pressure. The microorganisms and test results were asfollows:

a) A lyophilized strain of KLEBSIELLA TERRIGENA (A.T.C.C. 33257) wasrehydrated in phosphate-buffered saline (PBS) and was subcultivated inorder to obtain a broth with a bacterial density of 10⁹ cfu/ml(cfu=colony forming units). The broth was treated to obtain media freemonodispersed bacterial cells. The bacterial solution was then dilutedin water to provide the test batch solution at an initial concentrationof 4.8×10⁷ cfu per 100 ml.

Microbiological monitoring of the test water was done throughout theexperiment. Sampling of the filtered water was done at intervalsprescribed by the: U.S.E.P.A. (protocol section 3.5.1 d 1(b)) with themembrane-filter technique for KLEBSIELLA described in: 17th edition ofStandard Methods for the examination of water and wastewater, pp. 9-97to 9-99.

A test solution containing KLEBSIELLA TERRIGENA (A.T.C.C. 33257) at aninitial concentration of 4.8×10⁷ per 100 ml was passed through the fixedbed of each resin at a flow rate of 125 ml/min to 200 ml/min. Thetreated volume of solution for each resin was 150 liters in total.Sampling of the effluent or treated solution was effected at intervalscorresponding with a predetermined percentage of the test portionshaving passed through the resins. The results are shown in Table 6abelow:

                  TABLE 6a                                                        ______________________________________                                        Total % of test                                                                             Microorganism concentration in test                               solution passed effluent for each resin type (cfu/ml)                       through the resin                                                                           Resin I-D   Resin I-A                                           ______________________________________                                         0%           0/0/0       0/0/0                                                 25% 0/0/0 0/0/0                                                               50% 0/0/0 0/0/0                                                               60% 0/0/0 0/0/0                                                               75% 0/0/0 0/0/0                                                               90% 0/0/0 0/0/0                                                               100%  0/0/0 0/0/0                                                           ______________________________________                                    

As may be seen from table 6a the destruction of the bacteria was totalin the case of each resin.

b) Poliovirus 1 (A.T.C.C VR-59) was obtained as a lypholized pellet,rehydrated in PBS, and grown on buffalo green monkey (BGM) kidney cellsfrom the Armand Frappier Institute (IAF) in Laval Quebec. Standard cellculture and virological procedures were used to obtain a concentrationof 3×10⁷ of monodispersed virion particles per ml. Enough virus wasadded to a holding tank to obtain a concentration of about 1×10⁷ pfu perliter for the test batch solution (pfu=plaque-forming units).

The assay technique consisted of inoculating healthy BGM cells with asmall amount of filtered water at regular intervals. If a virus particlewere present, a plaque would be observed on the cellular bed thru thegellified maintenance media which contained a vital stain.

A test solution containing Poliovirus 1 (A.T.C.C VR-59) at an initialconcentration of 1×10⁷ pfu per liter was passed through the fixed bed ofeach resin at a flow rate of 125 ml/min to 200 ml/min. The treatedvolume of solution for each resin was 150 liters in total. Sampling ofthe effluent or treated solution was effected at intervals correspondingwith a predetermined percentage of the test portions having passedthrough the resins. The results are shown in Table 6b below:

                  TABLE 6b                                                        ______________________________________                                        Total % of test                                                                             Virus concentration in test effluent                              solution passed for each resin type (pfu/l)                                 through the resin                                                                           Resin I-D   Resin I-A                                           ______________________________________                                         0%           0/0/0       0/0/0                                                 25% 0/0/0 0/0/0                                                               50% 0/0/0 0/0/0                                                               60% 0/0/0 0/0/0                                                               75% 0/0/0 0/0/0                                                               90% 0/0/0 0/0/0                                                               100%  0/0/0 0/0/0                                                           ______________________________________                                    

As may be seen from table 6b the destruction of the Poliovirus was totalin the case of each resin.

c) Rotavirus (A.T.C.C VR-899) was obtained, rehydrated in PBS, and grownon A-104 cells obtained from IAF. The method used to obtain the dilutedpoliovirus above was used with respect to the rotavirus. The yield forrotavirus grown on MA-104 cells was 2×10⁶ pfu/ml. After dilution in theholding tank the concentration of the virus was 1×10⁷ pfu per liter.

The assay techniques were similar to those used for poliovirus, only thecell type and vital stain changed since they are specific for each typeof virus. The same sampling strategy was applied.

A test solution containing Rotavirus (A.T.C.C VR-59) at an initialconcentration of 1×10⁷ per 100 ml was passed through the fixed bed ofeach resin at a flow rate of 125 ml/min to 200 ml/min. The treatedvolume of solution for each resin was 150 liters in total. Sampling ofthe effluent or treated solution was effected at intervals correspondingwith a predetermined percentage of the test portions having passedthrough the resins. The results are shown in Table 6c below:

                  TABLE 6c                                                        ______________________________________                                        Total % of test                                                                             Virus concentration in test effluent                              solution passed for each resin type (cfu/l)                                 through the resin                                                                           Resin I-D   Resin I-A                                           ______________________________________                                         0%           0/0/0       0/0/0                                                 25% 0/0/0 0/0/0                                                               50% 0/0/0 0/0/0                                                               60% 0/0/0 0/0/0                                                               75% 0/0/0 0/0/0                                                               90% 0/0/0 0/0/0                                                               100%  0/0/0 0/0/0                                                           ______________________________________                                    

As may be seen from table 6c the destruction of the Rotavirus was totalin the case of each resin.

EXAMPLE 7

An iodine bleed test was conducted on the Resin I-A and Resin I-Dmentioned above. The tests were conducted as follows:

A pressure syringe was filled with 20 grams of resin (inner chamber of 3cm×13 cm). Using a peristaltic pump 750 ml/min of R/O water (sterilized)was pumped through the syringe; the resin being maintained in thesyringe by suitable mesh means. The total water passed through the resinwas 5 liters.

The results of the tests are given in the graph shown in FIG. 1; i.e.ppm iodine in effluent vs total volume water passed through resin. Thebleed test results as shown in the graph compares iodine (I₂) and iodide(I⁻) in effluent of treated water after passing through each of theresins.

EXAMPLE 8

The bacteriocidal longevity of the Resin I-A and Resin I-D weredetermined for purposes of comparison. Two fixed resin bed devices wereprovided, one device loaded with one of the resins and the other deviceloaded with the other resin; each device was loaded with 75.00 grams ofa respective resin. The tests for each resin bed were conductedsimultaneously. For each resin bed, the solution to be treated waspassed therethrough at a flow rate of 2.0 liters per minute, with aninitial concentration of Klebsiella Terrigena 1×10⁷ cfu/100 ml. Theeffluent was tested at intervals for the presence of viable bacteria. Asmay be seen in the graph of FIG. 2, the volume of contaminated solutionat which bacteria start to pass through the prior art resin (i.e. ResinI-D) is significantly less than the breakthrough volume for the resin ofthe present invention (i.e. Resin I-A). From FIG. 2 it may be seen thatthe bacteriocidal activity of the disinfectant resin of the presentinvention (Resin I-A) is superior to that of the known resin (ResinI-D), i.e. the Resin I-A has about a 16% superior antimicrobial activityin relation to the amount of water treatable by a given amount ofdisinfectant resin.

EXAMPLE 9 Preparation of Resin I-A' of the Present Invention

An iodinated resin (Resin I-A') was prepared following the procedures ofexamples 1 to 4 except that for the resin, Amberlite IR-400 (OH⁻) (wasused and for the procedure of example 3 the elevated temperature andpressure conditions were set at 121° C. and 15 psig respectively. ResinI-A' was used in the following examples.

EXAMPLE 10 Comparative Iodine Content in Effluent Air

Two cartridges as illustrated in FIGS. 3 and 4 were prepared. Eachcartridge contained 50.0 grammes of dry (granular) resin (i.e. and noactivated carbon bed). One cartridge contained Resin I-A' and the othercontained Resin I-D.

The cartridges were each disposed in a system as illustrated in FIG. 5but which did not contain any atomizer indicated generally by thereference number 7. The system included a housing 8 for defining an airpath and had an air inlet 9. The resin cartridge 1 was disposed at theoutlet of the air path. The air leaving the cartridge 1 was directed byappropriate tubing to a collector station 10. The system included avacuum pump 11 (but not the air sterilizer system 12) for drawing airfrom inlet 9 through the system.

In operation a cartridge 1 was releasably placed in position (e.g. snapfit, etc.) and the vacuum pump activated so as to draw outside air(indicated by the arrow 13) into the housing 8. The air passed throughthe cartridge 1 as shown by the arrows 14. The air leaving the cartridge1 was then directed to the collector station 10. The air entering thecollector station 10 impinged upon a iodine collector solution 15(comprising double reverse osmosis water, i.e. R/O water) in thecollector station 10. Air leaving the collector station 10 thereafterpassed through the pump 11 and was exhausted to the outside air.

Using the above described system, each, cartridge was submitted to anair velocity therethrough of 0.7 Liter/per minute for a period of 50minutes. The collector station 10 included 50 ml purified R/O water (thewater was then subjected to standard optical coloration techniques (i.e.the Leuco violet technique as referred to in example 5.4 above), todetermine the total iodine content).

The results of the tests are shown in table 10a:

                  TABLE 10a                                                       ______________________________________                                        Resin type   total iodine (I.sub.2)                                           ______________________________________                                        Resin I-A'   0.4 ppm                                                            Resin I-D 1.1 ppm                                                           ______________________________________                                    

The results of the tests as shown in table 9a means that each gramme ofboth of the resin types will add a definite amount of iodine to theeffluent air, namely as indicated in table 10b.

                  TABLE 10b                                                       ______________________________________                                        Resin type iodine (I.sub.2) release per gram resin                            ______________________________________                                        Resin I-A' 0.014 Mg/m.sup.3 /gr                                                 Resin I-D 0.031 Mg/m.sup.3 /gr                                              ______________________________________                                    

Thus, for example, if a gas mask cartridge as discussed above contained50.0 gm of iodinated resin, the resins would emit the level of iodineset out in table 10c below

                  TABLE 10c                                                       ______________________________________                                        Resin type                                                                              iodine (I.sub.2) release                                            ______________________________________                                        Resin I-A'                                                                              0.7 Mg/m.sup.3 (= 50 gr × 0.014 mg/m.sup.3 /gr)                 Resin I-D 1.5 Mg/m.sup.3 (= 50 gr × 0.031 mg/m.sup.3 /gr)             ______________________________________                                    

The "Committee of the American conference of governmental industrialhygienist." emits the "threshold limit value" or T.L.V. for commonchemicals. The iodine T.L.V. is 1.0 Mg/m³ for air analysis for humanbreathing during a period of 8 hrs.

Thus, while the Resin I-D releases 50% more iodine than the maximumT.L.V. indicated above, the Resin I-A' (of the present invention)releases iodine at a level well below the T.L.V. The Resin I-A' couldthus be used without an iodine scavenger; this would, for example,simplify the construction of a gas mask cartridge. The known Resin I-Don the other hand could also be used but it would require some sort ofiodine scavenger (e.g. activated carbon) to obtain the necessary iodineT.V.L. level.

EXAMPLE 11 The Resin I-A' was Tested with Different Micro-organismsUnder Different Conditions for the Sterilization of Air EXAMPLE 11.1Direct Contact Sterilization Study

Resin I-A' was evaluated for its biocidal capacity on direct contactwith Klebsiella Terrigena in relation to a time reference and a humiditycontent variation; namely water content variations of 110%, 50% & 0%(relative to the weight of dry resin) and time variations of 2, 5, 10,and 15 seconds.

After preparing the three resins with their respective humidity content25 glass rods were sterilized. A vial containing 25 ml of the inoculum(Klebsiella Terrigena: 10⁹ ×ml) was also prepared.

The testing proceeded as follows with respect to the dry resin. A glassrod was immersed in the inoculum and then immersed in the dry resin for2 seconds. The glass rod was then washed in 100 ml phosphate buffer towash out the microorganisms. Following the standard method forevaluation of water, the collected sample was then plated and incubated.

This procedure was then repeated for 5, 10 and 15 seconds.

The procedure was also repeated for the two other different humiditycontent batches of Resin I-A'. The results of the test are shown intable 11a.

                  TABLE 11a                                                       ______________________________________                                                  number of viable microorganisms                                       per time period                                                             % humidity  2 sec. 5 sec.     10 sec.                                                                             15 sec.                                   ______________________________________                                        110%        16     0          0     0                                            50% 23 1 0 0                                                                  0% 67 15  0 0                                                              ______________________________________                                    

As may be seen from table 11a, the Resin I-A' whether wet, humid or drydestroys large quantities of resistant bacteria in direct contact, andthis destruction occurs on a relatively rapid time base as demonstratedabove.

EXAMPLE 11.2 Klebsiella Terrigena Edradication Study: Air Flow

A study was done to evaluate the biocidal effectiveness of dry ResinI-A' versus Klebsiella Terrigena.

The system used was the system illustrated in FIG. 5. The systemincluded an atomizer 7 (of known construction) disposed in a housing 8provided with an air opening 9. The system had a vacuum pump 11 for thedisplacement of air through the system. The system included an airsterilizer 12 comprising a hollow housing 10 inches high by about 2.5inches in inner diameter and filled with about 1.5 kilograms of ResinI-A'; the sterilizer has an air inlet and outlet. The air path throughthe cartridge 1 is designated by the arrows 14. The atomizer 7 containedan inoculum 16 (Klebsiella Terrigena: 10⁷ ×100 ml). For the test, theair flow at arrow 13 was set at 30 liters per minute and the air inflowat arrow 17 for the atomizer was set at 8 liters per minute; theatomizer 7 injected mist or spray 18 of inoculum into the air in the airpath and the inoculated air then passed through cartridge 1 as shown bythe arrows 14.

A cartridge 1 as illustrated in FIGS. 3 and 4 was prepared using dryResin I-A' (65.0 gm giving a bed depth of 1.15 cm). The cartridge 1 wassubmitted to an injection of a total of 10 ml of inoculum over a timeperiod of 15 minute. Sampling was done at 0 minutes, 7.5 minutes and at15 minutes. The samples were collected in a standard impinger (i.e.collect ststion 10) as shown in FIG. 5. After, processing 100 ml of thewater from the impinger on microbiological paper filter and incubation,the results show total eradication of Klebsiella Terrigena.

EXAMPLE 11.3 BACILLUS PUMILUS Eradication: Air Contact

A study was carried out using the system shown in FIG. 6.

To the extent that members of the system are the same as those used inthe system illustrated in FIG. 5, the same reference numerals are usedto identify the same parts. The main difference between the system ofFIG. 5 and that of FIG. 6 is that the system of FIG. 6 uses amicrobiological filter paper 19 to collect the microorganisms leavingthe cartridge 1; the filter paper is maintained in place in any (known)suitable fashion.

An inoculum 20 of the thermophilic bacteria Bacillus Pumilus wasprepared and injected at a concentration of 10³ /liter of influent air.A cartridge mask containing 65.00 gm of Resin I-A' was prepared as forthe previous example. The test ran for 30 minutes.

All effluent (velocity at arrow 13 being 30 liters per minute) wascollected on the microbiological filter paper 19 (from millepore), thenlain in a T.S.A. (trypticase Soy Agar) and incubated. the results showedtotal eradication of Bacillus Pumilus.

EXAMPLE 11.4 BACILLUS SUBTILIS Sterilization in Air Flow

This test was performed with Bacillus Subtilis in a mixture of 40%active bacteria/60% spores. The system shown in FIG. 6 was used with thecartridge comprising 50 grams of Resin I-A' (giving a bed depth of 0.85cm). The controlled concentration of processed air was 55bacteriological units per liter. The air velocity was 23 liter perminute for 80 minutes.

Once the 80 minutes ended, the millepore filter paper was collected,lain on T.S.A. (after neutralisation of potential iodine with sodiumthiosulfate 5%) and incubated for 48 hours at 37 degree celsius. Theresults show a total eradication of micro-organisms.

EXAMPLE 11.5 BACILLUS SUBTILIS: Resin I-A' Versus Glass Beads in AirFlow

In order to assess the retention factor of micro-organisms on inertmaterials this test was performed. Also, to evaluate the migrationfactor of the biological vector, a sequential incubation was performed.

Two gas cartridges were built in accordance with FIGS. 3 and 4, namely:

    ______________________________________                                        a) Resin I-A' cartridge                                                                   10 micron polypropylene upstream mesh (filter);                      50.00 gm of Resin I-A' giving a bed depth                                     of .85 cm;                                                                    10 Micron polypropylene downstream mesh                                       (filter).                                                                    b) Glass bead cartridge 10 micron polypropylene upstream mesh (filter);        50.0 gm sterile glass beads (from Fisher                                      Scientific and having the same size as the beads                              of Resin I-A') giving a bed depth of .85 cm;                                  and                                                                           10 Micron polypropylene downstream mesh                                       (filter).                                                                  ______________________________________                                    

The system as shown in FIG. 6 was used for the tests.

Simultaneously, the two cartridges were, once inserted in theirrespective testing chamber, submitted to a velocity of 23 liter perminutes for 40 minutes with a microbiological load of 40 bacteria perliter in the influent.

Once the test period completed, the two cartridges were dissected insterile conditions and the microbiological filter paper recovered. Eachmaterials composing the masks were individually as well as the filterpaper were incubated in T.S.A. for 48 hours at 37 degree celsius. Theresults are shown in table 11b.

                  TABLE 11b                                                       ______________________________________                                                        Resin I-A'                                                                             Glass beads                                          ______________________________________                                        upstream mesh     2 cfu      tnc*  cfu                                          Resin\beads 0 cfu tnc* cfu                                          downstream mesh 0 cfu 220 cfu                                                 microbiological filter paper 0 cfu 86 cfu                                   ______________________________________                                         *tnc = microorganisms too numerous to count                              

As may be seen from table 11b the Resin I-A' eradicated all bacteria andno living micro-organism can live in the resin bed.

The Glass beads on the other hand have a mechanical filtering capacityin regards to the biological vector but migration occurs rapidly thusobtaining "tnc" results (too numerous to count) on the upstream mesh andthe beads themselves. The migration keeps on going through the filteruntil it reaches the microbiological paper filter in large number. Also,the glass beads filter becomes severely contaminated, causing a disposalproblem.

EXAMPLE 11.6 BACILLUS SUBTILIS: Resin Bed Depth Comparison

This test was performed to establish the biocidal effectiveness of theResin I-A' in regards to the microbiological eradication of BacillusSubtilis. The system of FIG. 6 was used.

Two cartridges as illustrated in FIGS. 3 and 4 containing respectively30.00 gm (giving a bed depth of 0.5 cm) and 50.00 Gr (giving a bed depthof 0.85 cm) of Resin I-A were submitted to 60 minutes of air pumping ata velocity of 27 liter per minutes. A total of 23 ml of inoculum at aconcentration of 10⁷ per ml were injected into the system.

A positive control yielded a concentration of 275 cfu/liter of air atthe microbiological sampling site.

The results show total eradication for both cartridges.

EXAMPLE 11.7 BACILLUS SUBTILIS: Longevity Study in Air Flow

A cartridge of FIGS. 3 and 4 containing 30.00 gr (bed depth: 0.5 cm) ofResin I-A' was submitted to an air flow velocity of 25 liter/minutecontaining a concentration of Bacillus Subtilis of 112 cpu/liter(positive control for correlation) for a period of 3 hrs.

The test was done using the impinger technique (of FIG. 5), with 300 mlof sterile water. Once the 3 hours completed the water from the impingerwas filtered on a microbiological membrane as referred in standardmethod for analysis of water and waste water 17 th edition, pp.9-97 To9-99. The growth media was trypticase soy agar. The results afterincubation for 48 hours at 37.5 degree celsius was total eradication.

EXAMPLE 12 Studies of the Fixation of Iodine at Different IodineConcentrations

Resin I-A', Resin I-B', Resin I-B" and Resin I-A" were prepared asfollows:

Resin I-A' was prepared as described in example 9.

Resin I-B' was prepared following the procedures of examples 1 and 2except that for the resin, Amberlite IR-400 (OH⁻) (from Rohm & Hass) wasused.

Resin I-B" was prepared following the procedures of examples 1 and 2(using Amberlite 401-S) except that the amount of the I₂ /KI mixture wasadjusted so as to provide a resin comprising about 30 percent iodine atthe end of the procedure in example 2; the mixture obtained at the endof the procedure of example 2 was divided into two equal parts and onepart was subjected to a wash to provide the iodinated resin obtained asat the end of the procedure in example 2; and

Resin I-A" was prepared by taking the remaining one half part of theintermediate mixture obtained in the preparation of Resin I-B"(mentioned above) and subjecting the mixture to the procedure of example3 except that the elevated temperature and pressure conditions were setat 121° C. and 15 psig respectively.

The iodine content of the above iodinated resins was determined inaccordance with the procedure outlined in example 5.3. The resins werealso subjected to an iodine bleed test as outlined in example 7. Theresults are shown in table 12 below:

                  TABLE 12                                                        ______________________________________                                        Resin type     Iodine % Iodine leach                                          ______________________________________                                        Resin I-B'     43.5     0.15       ppm                                          Resin I-A' 41.8 0.05 ppm                                                      Resin I-B" 30.5 0.3 ppm                                                       Resin I-A" 29.0 0.05 ppm                                                    ______________________________________                                    

As may be seen from table 12, subjecting the resin to a hightemperature/pressure treatment results in the iodine being moretenaciously fixed to the resin at different iodine concentrations.

EXAMPLE 13 Air Study with I-B"

The procedure of example 11.6 was followed using 30 grams of Resin I-B"and Bacillus Subtilis at a concentration of 275000 cfu per cubic meter.It was found that the Resin I-B" eradicated only 7 to 10% of themicroorganisms. The results of the test show that the Resin I-B" is notas effective at eradicating microorganisms from air as is the ResinI-A'; it would be necessary to have substantially more of Resin I-B" inorder to totally sterilize air as compared with the Resin I-A'.

EXAMPLE 14 Studies of the Fixation of Iodine at Different Temperaturesas Well as at Atmospheric and Elevated Pressures

Resin 1A, Resin 2B, Resin 3A and Resin 4B were prepared as follows:

The starting resin was Amberlite 402 (OH⁻) from Rohm & Hass. 1000 gramsof this resin was pretreated following the procedure outlined in example1(i). The obtained washed resin was divided into four 200 gram portions.An iodine sludge (four portions, one for each of the above mentioned 200gm portions of resin) was prepared as outlined in example 1(ii) butusing twice the amount of materials such as the iodine and the potassiumiodide. The 200 gm resin portions were each iodinated using a respectiveiodine sludge as follows:

Resin 1A was prepared, using an above mentioned 200 gm resin portion anda respective iodine sludge, following the procedures of examples 2 to 4except that for the procedure of example 3 the elevated temperature andpressure conditions were set at 121° C. and 15 psig respectively (whilethe reaction time at the elevated conditions remained at 15 minutes);

Resin 2B was prepared, using an above mentioned 200 gm resin portion anda respective iodine sludge, following the procedure of example 2 exceptthat the temperature of the shaking bath was maintained at 40° C.;

Resin 3A was prepared, using an above mentioned 200 gm resin portion anda respective iodine sludge, following the procedures of examples 2 to 4except that for the procedure of example 3 the elevated temperature andpressure conditions were set at 121° C. and 15 psig respectively whilethe reaction time at these elevated conditions was set at 1.5 hoursrather than at 15 minutes; and

Resin 4B was prepared, using an above mentioned 200 gm resin portion anda respective iodine sludge, following the procedure of example 2 exceptthat the reaction mixture was placed into a container having a loosefitting cover; the container containing the reaction mixture was placedinto a heated water bath; the temperature of the reaction mixture wasbrought up to a boiling temperature of 100° C. to 105° C. over a periodof 20 minutes and was maintained at the boiling temperature og 100° C.to 105° C. for a period of 15 minutes; and thereafter the mixture wasallowed to cool to room temperature over a period of about 1 hour (thereactor was not a pressure sealed reactor but one wherein the loosefitting cover allowed gas\vapour to escape such that the reaction wascarried out (essentially) at atmospheric pressure--extra safetyprecautions had to be taken due to the violent sputtering of thereaction mixture and to the toxicity of the released gas\vapour).

The density of each of the obtained iodinated resins was determined inaccordance with the procedure outlined in example 5.1. The iodinecontent of the above iodinated resins was determined in accordance withthe procedure outlined in example 5.3. The resins were also subjected toan iodine bleed test as outlined in example 7. The results are shown intable 14 below:

                  TABLE 14                                                        ______________________________________                                        Resin type                                                                             Iodine %     Iodine leach                                                                            Density                                       ______________________________________                                        Resin 1A 46.4         0.5 ppm   1.616 gm\ml                           Resin 2B 48.1 1.5 ppm 1.695 gm\ml                                   Resin 3A 45.0 0.5 ppm 1.661 gm\ml                                   Resin 4B 45.7 1.0 ppm 1.595 gm\ml                                 ______________________________________                                    

As may be seen from table 14, subjecting the starting iodine\resinmixture to a treatment at essentially atmospheric pressure and atemperature of 100° C. to 105° C. or lower (resin 2B and 4B) does notresult in the iodine being as tenaciously fixed to the resin as whenusing both a temperature above 100° C. and a pressure above atmosphericpressure (resins 1A and 3A).

EXAMPLE 15 Sterilisation Barrier Combinations for Use as Wound(Sterilisation) Dressings EXAMPLE 15.1 Preparation of Sterilisation FoamDressing

The following starting materials were used to prepare a sterilisationfoam dressing:

a particulate iodinated resin prepared in accordance with example 9above; the resin comprising particles or beads of about 0.3 mm to about0.7 mm;

R/O water; and

as foam precursor, HYPOL foamable hydrophilic polyurethane polymer,(code: #FHP2002) from W.R. Grace & Co., Organic Chemicals Division,Lexington, Mass. 02173.

The sterilisation foam barrier was prepared as follows:

150 ml of R/O water was placed into a 300 ml beaker. The water washeated to 50° C. 10 cc of the HYPOL and 10 gm of the iodinated resinwere simultaneously admixed with the heated water; mixing wasaccomplished with a magnetic stirring rod and was carried out before andafter the addition of the HYPOL and the resin for the purpose ofdispersing the resin particles as homogeneously as possible throughoutthe mixture. The obtained foam was set or cured in about 7 minutes; theresin particles were dispersed throughout the matrix cf the foam whichwas of porous cellular structure (i.e. sponge like). Once set theobtained flexible foam had a semi-sphere like form (see for example FIG.9); slices of this foam material were taken so as to provide a foamdressing having an essentially flat face for being applied against awound. The obtained sterilisation foam was flexible and sponge like inthat it could absorb liquids such as water, pus and the like.

EXAMPLE 15.2 Preparation of a Band-aid Like Sterilisation Dressing

The following starting materials were used to prepare a band-aidsterilisation dressing:

a particulate iodinated resin prepared in accordance with example 4above; the resin comprising particles or beads of about 0.3 mm to about0.7 mm; and

a strip of polymeric material having an adhesive on one face thereof(the strip was Compeed).

The sterilisation strip barrier was prepared as follows:

An open ended ring funnel was disposed over a central area of the stripon the adhesive face thereof. Resin beads were placed in the stem of thering funnel so as to essentialy cover the central portion of theadhesive face defined by the ring; a plunger was shoved into the ringand a mild pressure was applied to the resin beads therein. The ring wasremoved along with excess resin beads so as to leave behind a singlelayer of resin beads fixed to the adhesive face of the strip; the resinbeads in the layer essentialy abutted each other. The strip barrier hada form as shown in FIG. 8; if desired the beads do not have to abut butcould be spaced apart.

EXAMPLE 15.3 Animal Infection Study: Cuts

The foam type sterilisation dressing obtained from example 15.1 wastested as follows:

Eight male guinea pigs were shaved so as to expose essentially the sameskin area. The guinea pigs each weighed about 500 to 550 gm and wereobtained from Charles River, Quebec, Canada, a sub-division of Bausch &Lomb; the guinea pigs were quarantined for a period of 48 hours beforebeing prepared for and subjected to the tests.

The guinea pigs were prepared for the tests as follows:

Essentially the same area of skin of each of the guinea pigs wasanesthetised using Carbocaine-V (chlorhydrate of Mepivacaine USP 2%);this anesthetic has no known sterilisation qualities. An inoculumcomprising a mixture of Staphillococus Aureus and Pseudomonas Aeriginosawas prepared at 10⁹ cfu/ml; the ratio of Staphillococus Aureus toPseudomonas Aeriginosa was 1:1. 0.2 ml of the inoculum was injectedunder the anesthetised skin of each animal. A cruciform structuredscalpel cut (#) was made above the inoculum injection area of each ofthe animals; i.e. the cuts were 1.0 to 4.0 cm long and 1.0 to 4.0 mmdeep. Additional inoculum was dabbed onto the surface cuts.

The animals were divided into two groups of four animals each, one groupto be used as a control group and the other group as a test group. Afoam sterilisation dressing was applied over the wound for each of theanimals of the test group, i.e. the foam dressing was placed in contactwith the wounded skin area and maintained in place during the period ofthe test. The foam dressings were maintained in place over the woundarea by means of an adhesive strip which was provided with an opening orwindow by means of which a portion of the foam dressing was leftuncovered and exposed to the air. No dressing or sterilisation materialwas applied to the wounds of the animals of the control group.

The four animals of the test group with dressings developed no infectionand the scaring process was initiated after 16 hours. On the other handthe four control animals developed infection and the infection was stillspreading after 72 hours.

The strip type sterilisation dressing obtained from example 15.2 wastested exactly as above for the foam dressing with exactly the sameresults.

EXAMPLE 15.4 Animal Infection Study: Burns

The same studies as described in example 15.3 were carried out exceptthat the lesion was a burn created with a 1.0 cm red hot rod; the hotrod was firmly held against the skin for about 3 to 4 seconds. The sameInoculum as in example 15.3 was injected beneath the burn area and alsodabbed onto the surface of the burned skin. Exactly the same resultswere obtained for the two types of dressings as were obtained for thetests of example 15.3.

EXAMPLE 15.5 Animal Infection Study: Cuts with Continual Contact withInfectious Liquid

The foam type sterilisation dressing obtained from example 15.1 wastested as follows:

Four male guinea pigs were shaved so as to expose essentially the sameskin area. The guinea pigs each weighed about 500 to 550 gm and wereobtained from Charles River, Quebc, Canada; the guinea pigs werequarantined for a period of 48 hours before being prepared for andsubjected to the tests.

The guinea pigs were prepared for the tests as follows:

Essentially the same area of skin of each of the guinea pigs wasanesthetised using Carbocaine-V (chlorhydrate of Mepivacaine USP 2%);the area was also sterilised using 70% isopropyl alcohol. A cruciformstructured scalpel cut (#) was then made in the sterilised area; i.e.the cuts were 1.0 to 4.0 cm long and 1.0 to 4.0 mm deep.

The animals were divided into two groups of two animals each, one groupto be used as a control group and the other group as a test group. Afoam sterilisation dressing was applied over the wound for each of theanimals of the test group, i.e. the foam dressing was placed in contactwith the wounded skin area and maintained in place during the period ofthe test. The foam dressings were maintained in place over the woundarea by means of an adhesive strip which was provided with an opening orwindow by means of which a portion of the foam dressing was leftuncovered and exposed. No dressing or sterilisation material was appliedto the wounds of the animals of the control group.

An inoculum comprising a mixture of Staphillococus aureus andPseudomonas Aeriginosa was prepared at 10⁷ cfu/100 ml; the ratio ofStaphillococus Aureus to Pseudomonas Aeriginosa was 1:1. Sufficientinoculum was prepared such that each of the animals of the test andcontrol group could be bathed in the inoculum such that the bath liquidwas in continual contact with the wound area, i.e. the bath liquidcovered the dressings. The animals of each group were kept in the bathinoculum for a period of 72 hours.

The two animals of the test group with dressings developed no infectionand the scaring process was in full process. On the other hand the twocontrol animals each had developed infection.

EXAMPLE 15.6 Animal Infection Study: Cuts Contacted with Aerosol BorneInfectious Agents

The same procedure as for example 15.5 was used except that instead ofbeing maintained in a bath of inoculum, the inoculum was applied usingan atomiser the same as that used for example 11.2 for artificialcreation of airborne infection of a wound; the inoculum used also had10⁹ cfu/ml rather than 10⁷ cfu/100 ml as in example 15.6. 4 ml of theinoculum was sprayed directly on the wound of the control animals and onthe dressing covering the wound of the test animals; the inoculum was soapplied every hour for 8 hours with 72 hours of incubation. The sameresults as in example 15.5 were obtained.

EXAMPLE 15.7 Skin Reaction Study: Iodine Tincture

Three male guinea pigs were shaved so as to expose essentially the sameskin area. The guinea pigs each weighed about 500 to 550 gm and wereobtained from Charles River, Quebec, Canada; the guinea pigs werequarantined for a period of 48 hours before being prepared for andsubjected to the tests.

The guinea pigs were prepared for the tests as follows:

Essentially the same area of skin of each of the guinea pigs wasanesthetised using Carbocaine-V (chlorhydrate of Mepivacaine USP 2%);the area was also sterilised using &O& isopropyl alcohol. A cruciformstructured scalpel cut (#) was made in the sterilised area; i.e. thecuts were 1.0 to 4.0 cm long and 1.0 to 4.0 mm deep.

An inoculum comprising a mixture of Staphillococus Aureus andPseudomonas Aeriginosa was prepared at 10⁹ cfu/ml; the ratio ofStaphillococus Aureus to Pseudomonas Aeriginosa was 1:1.

The inoculum was only dabbed onto the surface of the wounds of each ofthe animals (no injection of inoculum under the skin). It was found thata 5% iodine tincture locally applied on the wounds would neutraliseinfection provided that the iodine tincture was applied at 0.1 mldirectly after infection and every 2 hours thereafter for 10 hours; theiodine tincture was from Jean Coutu, Quebec, Canada--5% iodine, 3.3% KIand 75% ethanol. However, it was noted that the skin in the periphery ofthe wound was seriously devitalised because of the burning effect of thetincture i.e. of the iodine.

It was also found that the iodine tincture did not stop infection fromoccurring if inoculum was injected under the skin.

EXAMPLE 15.8 Skin Reaction Study: Sterilisation Dressings

Three male guinea pigs were shaved so as to expose essentially the sameskin area. The guinea pigs each weighed about 500 to 550 gm and wereobtained from Charles River, Quebec, Canada; the guinea pigs werequarantined for a period of 48 hours before being subjected to thetests.

A foam sterilisation dressing of example 15.1 was applied over a shaveskin area of each of the animals, i.e. the foam dressing was placed incontact with the shaved skin area and maintained in place during theperiod of the test. The foam dressings were maintained in place over theskin area by means of an adhesive strip which was provided with anopening or window by means of which a portion of the foam dressing wasleft uncovered and exposed to the air. The dressing was maintained inplace for a period of 3 weeks. The covered skin area was examined everytwo days. No redness, rash, inflammation, or any other reaction wasnoted; the covered skin remained healthy.

The above procedure was also carried out using a strip sterilisationdressing of example 15.2. However the dressing was maintained in placeonly for 7 days. Again, no redness, rash, inflammation, or any otherreaction was noted; the covered skin remained healthy.

FIGS. 7 to 11 illustrate a number of example embodiements ofsterilisation barrier combinations of the present invention; some ofthese combinations are also described in example 15 above.

FIG. 7 shows a partially cut away perspective view of a sterilisationbarrier dressing of tea-bag type construction wherein the iodinatedresin particles or beads (one of which is designated by the referencenumeral 30) are free flowing but are held together by being enveloped bya fluid (e.g. air-liquid) permeable envelope 31 of (known)pharmaceutically acceptable paper or gauze (e.g. a suitable sterilegauze from Johnson & Johnson, Canada). The paper or gauze is permeableto fluids such as air and water but is able to hold onto the particlesof iodinated resin enveloped thereby since any holes in the paper gauzeare sized to be smaller than the particles of resin. This type ofdressing may be made relatively small or relatively large keeping inmind the size of the lesion that it is intended to cover. The dressingmay be made by providing a sheet of paper or gauze, placing the desiredamount of resin particles thereon and then folding one side edge of thepaper or gauze over the resin particles 30 so as to overlay and abut theopposite side; these abuting side edges 32 and 33 as well as each of therespective side edges of the two pairs of adjacent side edges indicatedgenerally at 34 and 35 may be fixed together in any known manner, forexample by compression, stitching or by the use of any knownphamaceutically acceptable adhesive. The fixation of the sides is suchthat they will tend to maintain their integrity in the face of water,body fluids or body exudates (e.g. pus). The embodiment shown in FIG. 7is shown may be considered as essentially having a plurality of resinbead layers; it could of course have only a single such layer.

Alternatively, the sterilisation barrier may take on a band-aid typeaspect as shown in FIG. 8. The combination shown has a flexible carriercomponent 36. A central portion of one side of the carrier component 36has fixed thereto a plurality of beads or particles (one of which isdesignated by the reference numeral 37) of demand disinfectant iodinatedresin. The resin beads 37 are fixed to the surface by a suitableadhesive which is pharmacetically acceptable and which will maintain thebeads on the carrier component even if exposed to water or body fluidsor exudates. The portion of the band surface 38 which surrounds thecentrally disposed beads 36 may also be provided with any (known)adhesive which may for example be able to releasably stick thecombination to the skin (e.g. a latex based adhesive). The carriercomponent 36 may, as desired be permeable or impermeable to fluids suchas air, water, pus; prefereably, the carrier is permeable to gas such asair, water vapour, etc. at least in the region of the resin beads fixedthereto, i.e. this region is air breathable. The carrier component 36may be of any suitable pharmaceutically acceptable (plastics) material(e.g. the carrier component may be a porous hydrophobic materialpermeable to air and water vapour such as described in U.S. Pat. Nos.3,953,566 and 4,194,041--Gore-Tex). The carrier component complete withan adhesive face may be obtained from Peco Marketing ltd., Montreal,Quebec under the name "Compeed".

FIGS. 9, 10 and 11 show a number of further embodiments of thesterilisation barrier combination.

FIG. 9 shows a flexible sterilisation foam or sponge type dressing 39for wounds. The dressing comprises a flexible pharmaceuticallyacceptable foam matrix 40 having iodinated resin particles (one of whichis designated with the reference numeral 41) dispersed therein. The foammatrix 40 has a porous open cell structure such that it is permeable tofluids such as air and water and can absorb body liquids in the mannerof a sponge (e.g. the foam is hydrophilic and/or oil loving); the foambarrier is air breathable. The foam matrix 40 as shown has cells ofrelatively small size so as to facilitate the absorption of liquids suchas pus. The resin particles 41 making up the resin disinfectantcomponent are distributed throughout and held or fixed in place by thepolymeric matrix 40 such that surface portions of the resin particlesare exposed within the cells of the matrix 40. The exposed surfaces ofthe resin are available for contact with any microorganisms which mayfind their way into the cells of the body of the barrier combination;contact with the resin devitalises the microorganisms.

The foam sterilisation barrier or dressing 39 as shown in FIG. 9 has asemi-spherical like shape. The flat surface 42 may be applied to a woundor cut. The dressing may be held in place by any suitable means such asfor example any suitable strapping or by adhesive tape means.Preferably, the sterilisation foam dressing 39 is held in place suchthat at least a portion of it is exposed (e.g. exposed to the air); thusthe means for holding the foam in place may be an adhesive strip whichhas a central opening exposing at least a portion of the foam when thefoam is held in place. Once in place on the wound, the flexible foamsterilisation barrier will sterilise the immediate area of the woundwhich it covers and also prevent other infectious microorganisms fromcontacting the wound from outside the body. Surprisingly, however, ithas been found that the sterilisation barrier is also effective not onlyagainst microorganisms at the immediate surface of a wound but alsoagainst those deeper within the body in the area of a cut.

FIG. 10 illustrates another type of flexible foam sterilisation barrier43. It differs from the sterilisation barrier shown in FIG. 9 in thatthe size of the cells (one of which is designated with the referencenumeral 44) is significantly larger than those for the foam shown inFIG. 9; this type of foam may be used as a liner material for wearingapparel to provide the apparel with the ability to protect the wearerfrom (skin) contact with viable microorganisms. The resin beads, spheresor particles (one of which is designated with the reference numeral 45)are, as in the case of the resin spheres 41 for the foam barrier 39 ofFIG. 9, dispersed in the foam matrix and are held or fixed in placethereby such that exposed surfaces of the resin are available forcontact with any microorganisms which may find their way into the cellsof the body of the barrier combination; contact with the resindevitalises the microorganisms.

The foam matrix for the sterilisation barriers of FIGS. 9 and 10 may bemade by admixing (known) starting reactants in (known) manner to make(known) foams which are pharmaceutically acceptable. Known polyurethanefoams may for example be used. In order to make the sterilisationbarrier, the disinfectant resin particles may be admixed with anddispersed (e.g. more or less homogeneously) in the starting reactants atthe beginning of the foam producing reaction. The foam barrier may beset in molds or else cut to the desired shape. The foam sterilisationbarrier may take any desired form such as sheets, films, plugs, and thelike; it may, for example, be molded so as to conform to the shape ofportion of the body to which it is to be applied.

As mentioned above a (flexible) phamaceutically acceptable hydrophilicfoam matrix may be obtained using water and HYPOL foamable hydrophilicpolyurethane polymer starting material from W.R. Grace & Co.Lexintington Mass. U.S.A..

The pore or cell size of the foam barrier may be adjusted in knownmanner; for example by altering the reaction temperature. For example inthe case of HYPOL a temperature of about 50 to 70° C. may be used toobtain small pore sizes and a lower temperature of about 35 to 45° C.may be used to obtainer larger sized pores.

FIG. 11 shows a cross sectional portion of a sandwich type textilematerial 46 which incorporates a flexible large cell size sterilisationfoam layer 47. The sandwich comprises two outer flexible cloth typelayers 48 and 49 which are fixed to the central sterilisation foambarrier 46 in any suitable manner (e.g. by an adhesive, melt fusion,etc.). The two outer layers 48 and 49 may be of any desired material;they may be permeable or impermeable to fluids such as air, watervapour, water and the like. They may for example be of cotton,polypropylene, etc.; or a Gore-tex type material mentioned above. Asheet of textile material as shown may cut into pieces of various shapesneeded to form such protective wearing apparel as may be desired, e.g.coats, pants, socks, face masks (e.g. full face masks or masks coveringonly the mouth and nose) and the like.

The flexible foam layer 47 can be made in any known manner provided thatdisinfectant resin particles are dispersed in the reaction mixtureduring the reaction such that the end product foam also has the resinparticles dispersed in the foam matrix and any microorganism able topenetrate into an interior cell of the foam may be able to contact aresin particle exposed into the cell and be devitalised thereby. Thefoam barrier as in the case of the foam dressings mentioned may beconfigured to be permeable to fluids such as air, water, etc..

The textile material 46 may be formed by first forming a sheet of thesterilisation foam; by providing sheets of the desired outer layers; andthen gluing the elements together such that the foam is sandwichedbetween the two other outer layers. Alternatively, a mold may be usedwherein opposed surfaces of the mold are provided with a respectiveouter layer; the foam starting materials are introduced between thelayers; and foaming activated such that the foam layer is produced insitu.

Although shown with two outer layers the combination of FIG. 11 may ofcourse have only one such cloth like layer. Additionally if the outerlayer or layers are permeable to fluids such as air, water, pus and thelike, the wearing apparel made therefrom could as needed double as akind of sterilisation dressing; the textile may thus for example be airbreathable.

Additionally although the foam sterilisation barrier has been describedin relation to a flexible foam it may be a stiff foam depending upon theapplication; again the stiff foam matrix may be prepared in knownmanner.

An alternate embodiement of the sandwich type textile may be madewherein the foam matrix is omitted; in this case the beads may be placedbetween the outer layers and the beads may be fixed in place for exampleby an adhesive or by melt fusion depending on the nature of the layers(e.g. melt fusion may be considered if the layers are of thermoplasticsmaterial; the textile may of course be so made as to preserve theflexibility of the combination.

I claim:
 1. A method for disinfecting air containing airbornemicroorganisms, said method comprising passing air containing airbornemicroorganisms through air path means and disinfecting such air in saidpath means by passing such air over a demand disinfectant resin suchthat airborne microorganisms contact said resin and are devitalizedthereby, said demand disinfectant resin comprising an iodinated strongbase anion exchange resin.
 2. A method for disinfecting air as definedin claim 1 wherein said iodinated strong base anion exchange resincomprises a strong base anion exchange resin component which representsfrom 25 to 90 percent by weight of the total weight of the iodinatedresin.
 3. A method for disinfecting air as defined in claim 1 whereinsaid iodinated strong base anion exchange resin comprises a strong baseanion exchange resin component which represents from 45 to 65 percent byweight of the total weight of the iodinated resin.
 4. A method fordisinfecting air as defined in claim 1 wherein said iodinated strongbase anion exchange resin is an iodinated strong base anion exchangeresin prepared in accordance with a process comprising a conversionstep, the conversion step comprising contacting a porous strong baseanion exchange resin in a salt form with a sufficient amount of aniodine-substance absorbable by the anion exchange resin such that theanion exchange resin absorbs said iodine-substance so as to convert theanion exchange resin to the demand disinfectant resin, saidiodine-substance being selected from the group comprising I₂ andpolyiodide ions having a valence of -1, characterized in that for theconversion steps at least a portion of the absorption ofiodine-substance is effected at elevated temperature and at elevatedpressure, said elevated temperature being higher than 100° C., saidelevated pressure being greater than atmospheric pressure.
 5. A methodfor disinfecting air as defined in claim 1 wherein said iodinated strongbase anion exchange resin is an iodinated strong base anion exchangeresin prepared in accordance with a process comprising a conversionstep, the conversion step comprising contacting a porous strong baseanion exchange resin in a salt form other than the iodide form I⁻, witha sufficient amount of an iodine-substance absorbable by the anionexchange resin such that the anion exchange resin absorbs saidiodine-substance so as to convert the anion exchange resin to the demanddisinfectant resin, said iodine-substance being selected from the groupcomprising polyiodide ions having a valence of -1, characterized in thatsaid conversion step comprises an initial conversion stage followed by asecond conversion stage, in that said initial conversion stage comprisescontacting the anion exchange resin with the iodine-substance at atemperature of 100° C. or lower so as to obtain an intermediatecomposition, said intermediate composition comprising residualabsorbable iodine-substance and an intermediate iodinated resin, and inthat said second conversion stage comprises subjecting the intermediatecomposition to elevated temperature and elevated pressure, said elevatedtemperature is a temperature of 102° C. or higher, said elevatedpressure is a pressure of from 2 psig to 35 psig and wherein saidiodine-substance comprises triiodide ions of formula I₃ ⁻, and whereinsaid anion exchange resin is in the hydroxyl form OH⁻ ; wherein theanion exchange resin is contacted with a composition consisting of amixture of KI, I₂ and a minor amount of water, the mole ratio of KI toI₂ initially being about
 1. 6. A system for disinfecting air containingairborne microorganisms, said system comprisingmeans for providing anair path for the movement of air therethrough,and a demand disinfectantresin disposed in said air path such that airborne microorganisms in airpassing through said air path are able to contact said resin and bedevitalized thereby,said demand disinfectant resin comprising aniodinated strong base anion exchange resin.
 7. A system for disinfectingair as defined in claim 6 wherein said iodinated strong base anionexchange resin comprises a strong base anion exchange resin componentwhich represents from 25 to 90 percent by weight of the total weight ofthe iodinated resin.
 8. A system for disinfecting air as defined inclaim 6 wherein said iodinated strong base anion exchange resincomprises a strong base anion exchange resin component which representsfrom 45 to 65 percent by weight of the total weight of the iodinatedresin.
 9. A system for disinfecting air as defined in claim 6 whereinsaid iodinated strong base anion exchange resin is an iodinated strongbase anion exchange resin prepared in accordance with a processcomprising a conversion step, the conversion step comprising contactinga porous strong base anion exchange resin in a salt form with asufficient amount of an iodine-substance absorbable by the anionexchange resin such that the anion exchange resin absorbs saidiodine-substance so as to convert the anion exchange resin to the demanddisinfectant resin, said iodine-substance being selected from the groupcomprising I₂ and polyiodide ions having a valence of -1, characterizedin that for the conversion step at least a portion of the absorption ofiodine-substance is effected at elevated temperature and at elevatedpressure, said elevated temperature being higher than 100° C., saidelevated pressure being greater than atmospheric pressure.
 10. A systemfor disinfecting air as defined in claim 6 wherein said iodinated strongbase anion exchange resin is an iodinated strong base anion exchangeresin prepared in accordance with a process comprising a conversionstep, the conversion step comprising contacting a porous strong baseanion exchange resin in a salt form other than the iodide form I⁻, witha sufficient amount of an iodine-substance absorbable by the anionexchange resin such that the anion exchange resin absorbs saidiodine-substance so as to convert the anion exchange resin to the demanddisinfectant resin, said iodine-substance being selected from the groupcomprising polyiodide ions having a valence of -1, characterized in thatsaid conversion step comprises an initial conversion stage followed by asecond conversion stage, in that said initial conversion stage comprisescontacting the anion exchange resin with the iodine-substance at atemperature of 100° C. or lower so as to obtain an intermediatecomposition, said intermediate composition comprising residualabsorbable iodine-substance and an intermediate iodinated resin, and inthat said second conversion stage comprises subjecting the intermediatecomposition to elevated temperature and elevated pressure, said elevatedtemperature is a temperature of 102° C. or higher, said elevatedpressure is a pressure of from 2 psig to 35 psig and wherein saidiodine-substance comprises triiodide ions of formula I₃ ⁻, and whereinsaid anion exchange resin is in the hydroxyl form OH⁻, wherein the anionexchange resin is contacted with a composition consisting of a mixtureof KI, I₂ and a minor amount of water, the mole ratio of KI to I₂initially being about
 1. 11. A system for disinfecting air as defined inclaim 6, said system including means for urging the air through said airpath.
 12. A system for disinfecting air as defined in claim 6, saidsystem including means disposed in said air path for scavenging iodineliberated from the disinfectant resin.